fix(buffer): avoid shared _extendedAttrs sentinel breaking addon-image

EMPTY_SPARSE_EXTENDED was shared across lines via copyFrom; addon-image
writes _extendedAttrs directly without copy-on-write, which caused tile
eviction failures and broke instanceof Object checks.

Use undefined for empty extended maps (keep EMPTY_SPARSE_MAP for _combined).
Ensure addon-image forks the map before writes and update the accessor test.

Co-authored-by: Daniel Imms <Tyriar@users.noreply.github.com>

.github/workflows/ci.yml

@@ -11,9 +11,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: 22.x
         cache: 'npm'
@@ -69,7 +69,7 @@ jobs:
           ./addons/addon-webgl/out/* \
           ./addons/addon-webgl/out-*st/*
     - name: Upload artifacts
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: build-artifacts
         path: compressed-build.zip
@@ -79,9 +79,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: 22.x
         cache: 'npm'
@@ -100,16 +100,16 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: 22.x
         cache: 'npm'
     - name: Install dependencies
       run: |
         npm ci
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v7
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -129,6 +129,7 @@ jobs:
         exit $EXIT_CODE
 
   test-unit:
+    needs: build
     timeout-minutes: 20
     strategy:
       matrix:
@@ -136,21 +137,16 @@ jobs:
         runs-on: [ubuntu, macos, windows]
     runs-on: ${{ matrix.runs-on }}-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
     - name: Install dependencies
       run: |
         npm ci
-    - name: Wait for build job
+    - uses: actions/download-artifact@v7
-      uses: NathanFirmo/wait-for-other-job@v1.1.1
-      with:
-        token: ${{ secrets.GITHUB_TOKEN }}
-        job: build
-    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -166,6 +162,7 @@ jobs:
       run: npm run test-unit --forbid-only
 
   test-integration:
+    needs: build
     timeout-minutes: 20
     strategy:
       matrix:
@@ -174,9 +171,9 @@ jobs:
         browser: [chromium, firefox, webkit]
     runs-on: ${{ matrix.runs-on }}
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
@@ -185,12 +182,7 @@ jobs:
         npm ci
     - name: Install playwright
       run: npx playwright install --with-deps ${{ matrix.browser }}
-    - name: Wait for build job
+    - uses: actions/download-artifact@v7
-      uses: NathanFirmo/wait-for-other-job@v1.1.1
-      with:
-        token: ${{ secrets.GITHUB_TOKEN }}
-        job: build
-    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -240,9 +232,9 @@ jobs:
       matrix:
         node-version: [22]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
@@ -251,7 +243,7 @@ jobs:
         npm ci
     - name: Install playwright
       run: npx playwright install
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v7
       with:
         name: build-artifacts
     - name: Unzip artifacts

.github/workflows/codeql-analysis.yml

@@ -24,12 +24,12 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v5
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v2
+      uses: github/codeql-action/init@v4
       with:
         languages: ${{ matrix.language }}
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v2
+      uses: github/codeql-action/autobuild@v4
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v2
+      uses: github/codeql-action/analyze@v4

.github/workflows/copilot-setup-steps.yml

@@ -18,9 +18,9 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Use Node.js 22.x
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v5
         with:
           node-version: 22.x
           cache: 'npm'

.github/workflows/release.yml

@@ -10,9 +10,9 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v5
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v5
       with:
         node-version: 22.x
         cache: 'npm'

addons/addon-attach/test/AttachAddon.test.ts

@@ -15,7 +15,7 @@ test.beforeAll(async ({ browser }) => {
 });
 test.afterAll(async () => await ctx.page.close());
 
-test.describe('Search Tests', () => {
+test.describe('AttachAddon', () => {
 
   test.beforeEach(async () => {
     await ctx.proxy.reset();

addons/addon-clipboard/src/ClipboardAddon.ts

@@ -78,13 +78,43 @@ export class BrowserClipboardProvider implements IClipboardProvider {
   }
 }
 
+/**
+ * TODO: Once the base64 handling on Uint8Arrays is more common,
+ * remove the btoa/atob fallbacks below.
+ */
+interface IUint8ArrayB64 extends Uint8Array {
+  toBase64(): string;
+}
+interface IUint8ArrayB64Ctor extends Uint8ArrayConstructor {
+  fromBase64(s: string): IUint8ArrayB64;
+}
+
 export class Base64 implements IBase64 {
   public encodeText(data: string): string {
-    return btoa(data);
+    const bytes = new TextEncoder().encode(data) as IUint8ArrayB64;
+    if (bytes.toBase64 !== undefined) {
+      return bytes.toBase64();
+    }
+    let bin = '';
+    for (let i = 0; i < bytes.length; i++) {
+      bin += String.fromCharCode(bytes[i]);
+    }
+    return btoa(bin);
   }
   public decodeText(data: string): string {
+    if ((Uint8Array as IUint8ArrayB64Ctor).fromBase64 !== undefined) {
+      try {
+        return new TextDecoder().decode((Uint8Array as IUint8ArrayB64Ctor).fromBase64(data));
+      } catch {}
+      return '';
+    }
     try {
-      return atob(data);
+      const bin = atob(data);
+      const bytes = new Uint8Array(bin.length);
+      for (let i = 0; i < bin.length; ++i) {
+        bytes[i] = bin.charCodeAt(i);
+      }
+      return new TextDecoder().decode(bytes);
     } catch {}
     return '';
   }

addons/addon-clipboard/test/ClipboardAddon.test.ts

@@ -29,7 +29,7 @@ test.describe('ClipboardAddon', () => {
       await ctx.page.context().grantPermissions(['clipboard-read', 'clipboard-write']);
     }
     await ctx.page.evaluate(`
-      window.term.reset()
+      window.term.reset();
       window.clipboard?.dispose();
       window.clipboard = new ClipboardAddon();
       window.term.loadAddon(window.clipboard);
@@ -92,4 +92,22 @@ test.describe('ClipboardAddon', () => {
       deepEqual(await ctx.page.evaluate(() => window.navigator.clipboard.readText()), '');
     });
   });
+
+  test.describe('non-ASCII', () => {
+    const testDataEncoded = '4oKsbWzDpMO8dMOf';
+    const testDataDecoded = '€mläütß';
+    test('write simple string', async () => {
+      await ctx.proxy.write(`\x1b]52;c;${testDataEncoded}\x07`);
+      deepEqual(await ctx.page.evaluate(() => window.navigator.clipboard.readText()), testDataDecoded);
+    });
+    test('read simple string', async () => {
+      await ctx.page.evaluate(`
+        window.data2 = [];
+        window.term.onData(e => data2.push(e));
+      `);
+      await ctx.page.evaluate((d) => window.navigator.clipboard.writeText(d), testDataDecoded);
+      await ctx.proxy.write(`\x1b]52;c;?\x07`);
+      deepEqual(await ctx.page.evaluate('window.data2'), [`\x1b]52;c;${testDataEncoded}\x07`]);
+    });
+  });
 });

addons/addon-image/README.md

@@ -90,7 +90,7 @@ terminal.loadAddon(imageAddon);
   therefore palette animations cannot be used.
 
 - **SIXEL Raster Attributes Handling**  
-  If raster attributes were found in the SIXEL data (level 2), the image will always be truncated to the given height/width extend. We deviate here from the specification on purpose, as it allows several processing optimizations. For level 1 SIXEL data without any raster attributes the image can freely grow in width and height up to the last data byte, which has a much higher processing penalty. In general encoding libraries should not create level 1 data anymore and should not produce pixel information beyond the announced height/width extend. Both is discouraged by the >30 years old specification.
+  If raster attributes were found in the SIXEL data (level 2), the image will always be truncated to the given height/width extent. We deviate here from the specification on purpose, as it allows several processing optimizations. For level 1 SIXEL data without any raster attributes the image can freely grow in width and height up to the last data byte, which has a much higher processing penalty. In general encoding libraries should not create level 1 data anymore and should not produce pixel information beyond the announced height/width extent. Both is discouraged by the >30 years old specification.
 
   Currently the SIXEL implementation of the addon does not take custom pixel sizes into account, a SIXEL pixel will map 1:1 to a screen pixel.
 
@@ -149,9 +149,9 @@ The addon provides the following API endpoints to retrieve raw image data as can
 
 ### Memory Usage
 
-The addon does most image processing in Javascript and therefore can occupy a rather big amount of memory. To get an idea where the memory gets eaten, lets look at the data flow and processing steps:
+The addon does most image processing in JavaScript and therefore can occupy a rather big amount of memory. To get an idea where the memory gets eaten, let's look at the data flow and processing steps:
-- Incomming image data chunk at `term.write` (terminal)  
+- Incoming image data chunk at `term.write` (terminal)  
-  `term.write` might stock up incoming chunks. To circumvent this, you will need proper flow control (see xterm.js docs). Note that with image output it is more likely to run into this issue, as it can create lots of MBs in very short time.
+  `term.write` might stack up incoming chunks. To circumvent this, you will need proper flow control (see xterm.js docs). Note that with image output it is more likely to run into this issue, as it can create lots of MBs in very short time.
 - Sequence Parser (terminal)  
   The parser operates on a buffer containing up to 2^17 codepoints (~0.5 MB).
 - Sequence Handler - Chunk Decoding (addon)  
@@ -177,18 +177,18 @@ const totalActive = storageBytes + decodingBytes;
 ```
 
 Note that browsers have offloading tricks for rarely touched memory segments, esp. `storageBytes` might not directly translate into real memory usage. Usage peaks will happen during active decoding of multiple big images due to the need of 2 full pixel buffers at the same time, which cannot be offloaded. Thus you may want to keep an eye on `pixelLimit` under limited memory conditions.  
-Further note that the formulas above do not respect the Javascript object's overhead. Compared to the raw buffer needs the book keeping by these objects is rather small (<<5%).
+Further note that the formulas above do not respect the JavaScript object's overhead. Compared to the raw buffer needs the bookkeeping by these objects is rather small (<<5%).
 
 _Why should I care about memory usage at all?_  
-Well you don't have to, and it probably will just work fine with the addon defaults. But for bigger integrations, where much more data is held in the Javascript context (like multiple terminals on one page), it is likely to hit the engine's memory limit sooner or later under decoding and/or storage pressure.
+Well you don't have to, and it probably will just work fine with the addon defaults. But for bigger integrations, where much more data is held in the JavaScript context (like multiple terminals on one page), it is likely to hit the engine's memory limit sooner or later under decoding and/or storage pressure.
 
 _How can I adjust the memory usage?_  
 - `pixelLimit`  
-  A constructor setting, thus you would have to anticipate, whether (multiple) terminals in your page gonna do lots of concurrent decoding. Since this is normally not the case and the memory usage is only temporarily peaking, a rather high value should work even with multiple terminals in one page.
+  A constructor setting, thus you would have to anticipate, whether (multiple) terminals in your page gonna do lots of concurrent decoding. Since this is normally not the case and the memory usage only peaks temporarily, a rather high value should work even with multiple terminals in one page.
 - `storageLimit`  
-  A constructor and a runtime setting. In conjunction with `storageUsage` you can do runtime checks and adjust the limit to your needs. If you have to lower the limit below the current usage, images will be removed in FIFO order and may turn into a placeholder in the terminal's scrollback (if `showPlaceholder` is set). When adjusting keep in mind to leave enough room for memory peaking for decoding.
+  A constructor and a runtime setting. In conjunction with `storageUsage` you can do runtime checks and adjust the limit to your needs. If you have to lower the limit below the current usage, images will be removed in FIFO order and may turn into a placeholder in the terminal's scrollback (if `showPlaceholder` is set). When adjusting keep in mind to leave enough room for peak memory use during decoding.
 - `sixelSizeLimit | iipSizeLimit | kittySizeLimit`  
-  Constructor settings. This has only a small impact on peaking memory during decoding. It is meant to avoid processing of overly big or broken image sequences at an earlier phase, thus may stop the invoked decoders from entering memory intensive tasks for potentially invalid data.
+  Constructor settings. This has only a small impact on peak memory during decoding. It is meant to avoid processing of overly big or broken image sequences at an earlier phase, thus may stop the invoked decoders from entering memory intensive tasks for potentially invalid data.
 
 
 ### Terminal Interaction

addons/addon-image/src/ImageStorage.ts

@@ -436,9 +436,9 @@ export class ImageStorage implements IDisposable {
       for (let col = 0; col < cols; ++col) {
         let e: IExtendedAttrsImage;
         if (line.getBg(col) & BgFlags.HAS_EXTENDED) {
-          e = line._extendedAttrs[col] ?? EMPTY_ATTRS;
+          e = line._extendedAttrs?.[col] ?? EMPTY_ATTRS;
         } else {
-          const maybeImg = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
+          const maybeImg = line._extendedAttrs?.[col] as IExtendedAttrsImage | undefined;
           if (!maybeImg || maybeImg.imageId === undefined || maybeImg.imageId === -1) {
             continue;
           }
@@ -461,7 +461,7 @@ export class ImageStorage implements IDisposable {
            * Also check _extendedAttrs directly for cells where text cleared HAS_EXTENDED.
            */
           while (++col < cols) {
-            const nextE = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
+            const nextE = line._extendedAttrs?.[col] as IExtendedAttrsImage | undefined;
             if (!nextE || nextE.imageId !== imageId || nextE.tileId !== startTile + count) {
               break;
             }
@@ -515,7 +515,7 @@ export class ImageStorage implements IDisposable {
     for (let row = 0; row < rows; ++row) {
       const line = buffer.lines.get(row) as IBufferLineExt;
       if (line.getBg(oldCol) & BgFlags.HAS_EXTENDED) {
-        const e: IExtendedAttrsImage = line._extendedAttrs[oldCol] ?? EMPTY_ATTRS;
+        const e: IExtendedAttrsImage = line._extendedAttrs?.[oldCol] ?? EMPTY_ATTRS;
         const imageId = e.imageId;
         if (imageId === undefined || imageId === -1) {
           continue;
@@ -560,7 +560,7 @@ export class ImageStorage implements IDisposable {
     const buffer = this._terminal._core.buffer;
     const line = buffer.lines.get(y) as IBufferLineExt;
     if (line && line.getBg(x) & BgFlags.HAS_EXTENDED) {
-      const e: IExtendedAttrsImage = line._extendedAttrs[x] ?? EMPTY_ATTRS;
+      const e: IExtendedAttrsImage = line._extendedAttrs?.[x] ?? EMPTY_ATTRS;
       if (e.imageId && e.imageId !== -1) {
         const orig = this._images.get(e.imageId)?.orig;
         if (window.ImageBitmap && orig instanceof ImageBitmap) {
@@ -580,7 +580,7 @@ export class ImageStorage implements IDisposable {
     const buffer = this._terminal._core.buffer;
     const line = buffer.lines.get(y) as IBufferLineExt;
     if (line && line.getBg(x) & BgFlags.HAS_EXTENDED) {
-      const e: IExtendedAttrsImage = line._extendedAttrs[x] ?? EMPTY_ATTRS;
+      const e: IExtendedAttrsImage = line._extendedAttrs?.[x] ?? EMPTY_ATTRS;
       if (e.imageId && e.imageId !== -1 && e.tileId !== -1) {
         const spec = this._images.get(e.imageId);
         if (spec) {
@@ -611,7 +611,7 @@ export class ImageStorage implements IDisposable {
 
   private _writeToCell(line: IBufferLineExt, x: number, imageId: number, tileId: number): void {
     if (line._data[x * Cell.SIZE + Cell.BG] & BgFlags.HAS_EXTENDED) {
-      const old = line._extendedAttrs[x];
+      const old = line._extendedAttrs?.[x];
       if (old) {
         if (old.imageId !== undefined) {
           // found an old ExtendedAttrsImage, since we know that
@@ -627,13 +627,13 @@ export class ImageStorage implements IDisposable {
           return;
         }
         // found a plain ExtendedAttrs instance, clone it to new entry
-        line._extendedAttrs[x] = new ExtendedAttrsImage(old.ext, old.urlId, imageId, tileId);
+        (line._extendedAttrs ??= {})[x] = new ExtendedAttrsImage(old.ext, old.urlId, imageId, tileId);
         return;
       }
     }
     // fall-through: always create new ExtendedAttrsImage entry
     line._data[x * Cell.SIZE + Cell.BG] |= BgFlags.HAS_EXTENDED;
-    line._extendedAttrs[x] = new ExtendedAttrsImage(0, 0, imageId, tileId);
+    (line._extendedAttrs ??= {})[x] = new ExtendedAttrsImage(0, 0, imageId, tileId);
   }
 
   private _evictOnAlternate(): void {
@@ -652,7 +652,7 @@ export class ImageStorage implements IDisposable {
       }
       for (let x = 0; x < this._terminal.cols; ++x) {
         if (line._data[x * Cell.SIZE + Cell.BG] & BgFlags.HAS_EXTENDED) {
-          const imgId = line._extendedAttrs[x]?.imageId;
+          const imgId = line._extendedAttrs?.[x]?.imageId;
           if (imgId) {
             const spec = this._images.get(imgId);
             if (spec) {

addons/addon-image/src/Types.ts

@@ -64,7 +64,7 @@ export interface IExtendedAttrsImage extends IExtendedAttrs {
 
 /* eslint-disable */
 export interface IBufferLineExt extends IBufferLine {
-  _extendedAttrs: {[index: number]: IExtendedAttrsImage | undefined};
+  _extendedAttrs: {[index: number]: IExtendedAttrsImage | undefined} | undefined;
   _data: Uint32Array;
 }
 

addons/addon-image/test/ImageAddon.test.ts

@@ -118,7 +118,10 @@ test.describe('ImageAddon', () => {
     }
     // bufferline privates
     strictEqual(await ctx.page.evaluate('window.term._core.buffer.lines.get(0)._data instanceof Uint32Array'), true);
-    strictEqual(await ctx.page.evaluate('window.term._core.buffer.lines.get(0)._extendedAttrs instanceof Object'), true);
+    strictEqual(await ctx.page.evaluate(`(() => {
+      const ea = window.term._core.buffer.lines.get(0)._extendedAttrs;
+      return ea === undefined || (typeof ea === 'object' && ea !== null);
+    })()`), true);
     // inputhandler privates
     strictEqual(await ctx.page.evaluate('window.term._core._inputHandler._curAttrData.constructor.name'), '_AttributeData');
     strictEqual(await ctx.page.evaluate('window.term._core._inputHandler._parser.constructor.name'), 'EscapeSequenceParser');

addons/addon-search/src/DecorationManager.test.ts

@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { DecorationManager } from './DecorationManager';
+import { SearchEngine } from './SearchEngine';
+import { SearchLineCache } from './SearchLineCache';
+import { Terminal } from 'browser/public/Terminal';
+import type { ISearchDecorationOptions } from '@xterm/addon-search';
+import type { IDecorationOptions } from '@xterm/xterm';
+import { DisposableStore } from 'common/Lifecycle';
+
+function writeP(terminal: Terminal, data: string): Promise<void> {
+  return new Promise(r => terminal.write(data, r));
+}
+
+describe('DecorationManager', () => {
+  let store: DisposableStore;
+  let terminal: Terminal;
+  let decorationManager: DecorationManager;
+
+  beforeEach(() => {
+    store = new DisposableStore();
+    terminal = store.add(new Terminal({ cols: 10, rows: 5 }));
+    decorationManager = store.add(new DecorationManager(terminal));
+  });
+
+  it('should split highlight decorations for a wrapped match', async () => {
+    await writeP(terminal, '0123456789abcde');
+    const searchEngine = new SearchEngine(terminal, store.add(new SearchLineCache(terminal)));
+    const match = searchEngine.find('9abc', 0, 0);
+    assert.ok(match);
+
+    const decorationOptions: IDecorationOptions[] = [];
+    const registerDecoration = terminal.registerDecoration.bind(terminal);
+    terminal.registerDecoration = (options: IDecorationOptions) => {
+      decorationOptions.push(options);
+      return registerDecoration(options);
+    };
+
+    const options: ISearchDecorationOptions = {
+      matchOverviewRuler: '#ff0000',
+      activeMatchColorOverviewRuler: '#00ff00'
+    };
+    decorationManager.createHighlightDecorations([match], options);
+
+    assert.strictEqual(decorationOptions.length, 2);
+    assert.strictEqual(decorationOptions[0].x, 9);
+    assert.strictEqual(decorationOptions[0].width, 1);
+    assert.strictEqual(decorationOptions[1].x, 0);
+    assert.strictEqual(decorationOptions[1].width, 3);
+
+    const withOverviewRuler = decorationOptions.filter(o => o.overviewRulerOptions !== undefined);
+    assert.strictEqual(withOverviewRuler.length, 2);
+  });
+
+  it('should only add one overview ruler marker per buffer line', async () => {
+    await writeP(terminal, 'abcdefghij');
+    const decorationOptions: IDecorationOptions[] = [];
+    const registerDecoration = terminal.registerDecoration.bind(terminal);
+    terminal.registerDecoration = (options: IDecorationOptions) => {
+      decorationOptions.push(options);
+      return registerDecoration(options);
+    };
+
+    const options: ISearchDecorationOptions = {
+      matchOverviewRuler: '#ff0000',
+      activeMatchColorOverviewRuler: '#00ff00'
+    };
+    decorationManager.createHighlightDecorations([
+      { term: 'a', col: 0, row: 0, size: 1 },
+      { term: 'f', col: 5, row: 0, size: 1 }
+    ], options);
+
+    const withOverviewRuler = decorationOptions.filter(o => o.overviewRulerOptions !== undefined);
+    assert.strictEqual(withOverviewRuler.length, 1);
+    assert.strictEqual(withOverviewRuler[0].x, 0);
+  });
+});

addons/addon-search/src/SearchEngine.ts

@@ -60,7 +60,7 @@ export class SearchEngine {
       this._terminal.clearSelection();
       return undefined;
     }
-    if (startCol > this._terminal.cols) {
+    if (startCol >= this._terminal.cols) {
       throw new Error(`Invalid col: ${startCol} to search in terminal of ${this._terminal.cols} cols`);
     }
 

addons/addon-search/test/SearchAddon.test.ts

@@ -417,7 +417,7 @@ test.describe('Search Tests', () => {
     test.describe('#2444 wrapped line content not being found', () => {
       let fixture: string;
       test.beforeAll(async () => {
-        fixture = (await new Promise<Buffer>(r => readFile(resolve(__dirname, '../fixtures/issue-2444'), (err, data) => r(data)))).toString();
+        fixture = (await new Promise<Buffer>((res, rej) => readFile(resolve(__dirname, '../fixtures/issue-2444'), (err, data) => err ? rej(err) : res(data)))).toString();
         if (process.platform !== 'win32') {
           fixture = fixture.replace(/\n/g, '\n\r');
         }
@@ -501,7 +501,7 @@ test.describe('Search Tests', () => {
         window.search.onDidChangeResults(e => window.calls.push(e));
       `);
       // Move cursor forward 1 time to create a null character, as opposed to regular whitespace
-      await ctx.proxy.write('\\x1b[CHi Hi');
+      await ctx.proxy.write('\x1b[CHi Hi');
       strictEqual(await ctx.page.evaluate(`window.search.findPrevious('h', { decorations: { activeMatchColorOverviewRuler: '#ff0000' } })`), true);
       deepStrictEqual(await ctx.page.evaluate('window.calls'), [
         { resultCount: 2, resultIndex: 1 }

addons/addon-unicode-graphemes/src/UnicodeGraphemesAddon.ts

@@ -2,7 +2,7 @@
  * Copyright (c) 2023 The xterm.js authors. All rights reserved.
  * @license MIT
  *
- * UnicodeVersionProvider for V15 with grapeme cluster handleing.
+ * UnicodeVersionProvider for V15 with grapheme cluster handling.
  */
 
 import type { Terminal, ITerminalAddon, IUnicodeHandling } from '@xterm/xterm';

addons/addon-web-links/src/WebLinkProvider.ts

@@ -57,7 +57,8 @@ function isUrl(urlString: string): boolean {
 
 export class LinkComputer {
   public static computeLink(y: number, regex: RegExp, terminal: Terminal, activate: (event: MouseEvent, uri: string) => void): ILink[] {
-    const rex = new RegExp(regex.source, (regex.flags || '') + 'g');
+    const flags = regex.flags.includes('g') ? regex.flags : `${regex.flags}g`;
+    const rex = new RegExp(regex.source, flags);
 
     const [lines, startLineIndex] = LinkComputer._getWindowedLineStrings(y - 1, terminal);
     const line = lines.join('');

addons/addon-web-links/src/WebLinksAddon.ts

@@ -7,13 +7,13 @@ import type { Terminal, ITerminalAddon, IDisposable } from '@xterm/xterm';
 import type { WebLinksAddon as IWebLinksApi } from '@xterm/addon-web-links';
 import { ILinkProviderOptions, WebLinkProvider } from './WebLinkProvider';
 
-// consider everthing starting with http:// or https://
+// consider everything starting with http:// or https://
 // up to first whitespace, `"` or `'` as url
 // NOTE: The repeated end clause is needed to not match a dangling `:`
 // resembling the old (...)*([^:"\'\\s]) final path clause
 // additionally exclude early + final:
 // - unsafe from rfc3986: !*'()
-// - unsafe chars from rfc1738: {}|\^~[]` (minus [] as we need them for ipv6 adresses, also allow ~)
+// - unsafe chars from rfc1738: {}|\^~[]` (minus [] for ipv6 addresses, also allow ~)
 // also exclude as finals:
 // - final interpunction like ,.!?
 // - any sort of brackets <>()[]{} (not spec conform, but often used to enclose urls)

addons/addon-webgl/README.md

@@ -23,7 +23,7 @@ See the full [API](https://github.com/xtermjs/xterm.js/blob/master/addons/addon-
 
 ### Handling Context Loss
 
-The browser may drop WebGL contexts for various reasons like OOM or after the system has been suspended. There is an API exposed that fires the `webglcontextlost` event fired on the canvas so embedders can handle it however they wish. An easy, but suboptimal way, to handle this is by disposing of WebglAddon when the event fires:
+The browser may drop WebGL contexts for various reasons like OOM or after the system has been suspended. There is an API exposed that fires the `webglcontextlost` event on the canvas so embedders can handle it however they wish. An easy, but suboptimal way, to handle this is by disposing of WebglAddon when the event fires:
 
 ```ts
 const terminal = new Terminal();

addons/addon-webgl/src/GlyphRenderer.ts

@@ -220,7 +220,7 @@ export class GlyphRenderer extends Disposable {
   public updateCell(x: number, y: number, code: number, bg: number, fg: number, ext: number, chars: string, width: number, lastBg: number): void {
     // Since this function is called for every cell (`rows*cols`), it must be very optimized. It
     // should not instantiate any variables unless a new glyph is drawn to the cache where the
-    // slight slowdown is acceptable for the developer ergonomics provided as it's a once of for
+    // slight slowdown is acceptable for the developer ergonomics provided as it's a one-off for
     // each glyph.
     this._updateCell(this._vertices.attributes, x, y, code, bg, fg, ext, chars, width, lastBg);
   }
@@ -389,8 +389,9 @@ export class GlyphRenderer extends Disposable {
     gl.bindTexture(gl.TEXTURE_2D, this._atlasTextures[i].texture);
     gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
     gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
     gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, atlas.pages[i].canvas);
-    gl.generateMipmap(gl.TEXTURE_2D);
     this._atlasTextures[i].version = atlas.pages[i].version;
   }
 

addons/addon-webgl/src/TextureAtlas.ts

@@ -69,7 +69,7 @@ export class TextureAtlas implements ITextureAtlas {
   private _overflowSizePage: AtlasPage | undefined;
 
   private _tmpCanvas: HTMLCanvasElement;
-  // A temporary context that glyphs are drawn to before being transfered to the atlas.
+  // A temporary context that glyphs are drawn to before being transferred to the atlas.
   private _tmpCtx: CanvasRenderingContext2D;
 
   private _workBoundingBox: IBoundingBox = { top: 0, left: 0, bottom: 0, right: 0 };
@@ -152,7 +152,7 @@ export class TextureAtlas implements ITextureAtlas {
   }
 
   private _createNewPage(): AtlasPage {
-    // Try merge the set of the 4 most used pages of the largest size. This is is deferred to a
+    // Try merge the set of the 4 most used pages of the largest size. This is deferred to a
     // microtask to ensure it does not interrupt textures that will be rendered in the current
     // animation frame which would result in blank rendered areas. This is actually not that
     // expensive relative to drawing the glyphs, so there is no need to wait for an idle callback.
@@ -191,7 +191,7 @@ export class TextureAtlas implements ITextureAtlas {
         return newPage;
       }
 
-      const sortedMergingPagesIndexes = mergingPages.map(e => e.glyphs[0].texturePage).sort((a, b) => a > b ? 1 : -1);
+      const sortedMergingPagesIndexes = mergingPages.map(e => e.glyphs[0].texturePage).sort((a, b) => a - b);
       const mergedPageIndex = this.pages.length - mergingPages.length;
 
       // Merge into the new page
@@ -1080,17 +1080,33 @@ class AtlasPage {
     size: number,
     sourcePages?: AtlasPage[]
   ) {
-    if (sourcePages) {
-      for (const p of sourcePages) {
-        this._glyphs.push(...p.glyphs);
-        this._usedPixels += p._usedPixels;
-      }
-    }
     this.canvas = createCanvas(document, size, size);
     // The canvas needs alpha because we use clearColor to convert the background color to alpha.
     // It might also contain some characters with transparent backgrounds if allowTransparency is
     // set.
     this.ctx = throwIfFalsy(this.canvas.getContext('2d', { alpha: true }));
+    if (sourcePages) {
+      if (sourcePages.length === 4) {
+        // optimized for quadmerge
+        this._glyphs = this._glyphs.concat(
+          sourcePages[0].glyphs,
+          sourcePages[1].glyphs,
+          sourcePages[2].glyphs,
+          sourcePages[3].glyphs
+        );
+        this._usedPixels = sourcePages[0]._usedPixels +
+          sourcePages[1]._usedPixels +
+          sourcePages[2]._usedPixels +
+          sourcePages[3]._usedPixels;
+      } else {
+        // fallback for non quadmerges (should never be used)
+        for (let i = 0; i < sourcePages.length; ++i) {
+          this._glyphs = this._glyphs.concat(sourcePages[i].glyphs);
+          this._usedPixels += sourcePages[i]._usedPixels;
+        }
+
+      }
+    }
   }
 
   public clear(): void {

addons/addon-webgl/src/WebglRenderer.ts

@@ -456,7 +456,18 @@ export class WebglRenderer extends Disposable implements IRenderer {
 
     for (y = start; y <= end; y++) {
       row = y + terminal.buffer.ydisp;
-      line = terminal.buffer.lines.get(row)!;
+      const bufferLine = terminal.buffer.lines.get(row);
+      if (!bufferLine) {
+        this._model.lineLengths[y] = 0;
+        for (x = 0; x < terminal.cols; x++) {
+          j = ((y * terminal.cols) + x) * RenderModelConstants.INDICIES_PER_CELL;
+          modelUpdated = true;
+          this._nullModelCell(x, y, j, 0, 0, 0);
+        }
+        this._setRowBlinkState(y, false);
+        continue;
+      }
+      line = bufferLine;
       let rowHasBlinkingCells = false;
       this._model.lineLengths[y] = 0;
       isCursorRow = cursorY === row;
@@ -587,13 +598,9 @@ export class WebglRenderer extends Disposable implements IRenderer {
           // Null out non-first cells
           for (x++; x <= lastCharX; x++) {
             j = ((y * terminal.cols) + x) * RenderModelConstants.INDICIES_PER_CELL;
-            this._glyphRenderer.value!.updateCell(x, y, NULL_CELL_CODE, 0, 0, 0, NULL_CELL_CHAR, 0, 0);
-            this._model.cells[j] = NULL_CELL_CODE;
             // Don't re-resolve the cell color since multi-colored ligature backgrounds are not
             // supported
-            this._model.cells[j + RenderModelConstants.BG_OFFSET] = this._cellColorResolver.result.bg;
+            this._nullModelCell(x, y, j, this._cellColorResolver.result.bg, this._cellColorResolver.result.fg, this._cellColorResolver.result.ext);
-            this._model.cells[j + RenderModelConstants.FG_OFFSET] = this._cellColorResolver.result.fg;
-            this._model.cells[j + RenderModelConstants.EXT_OFFSET] = this._cellColorResolver.result.ext;
           }
           x--; // Go back to the previous update cell for next iteration
         }
@@ -607,6 +614,14 @@ export class WebglRenderer extends Disposable implements IRenderer {
     this._updateTextBlinkState();
   }
 
+  private _nullModelCell(x: number, y: number, cellIndex: number, bg: number, fg: number, ext: number): void {
+    this._glyphRenderer.value!.updateCell(x, y, NULL_CELL_CODE, bg, fg, ext, NULL_CELL_CHAR, 0, 0);
+    this._model.cells[cellIndex] = NULL_CELL_CODE;
+    this._model.cells[cellIndex + RenderModelConstants.BG_OFFSET] = bg;
+    this._model.cells[cellIndex + RenderModelConstants.FG_OFFSET] = fg;
+    this._model.cells[cellIndex + RenderModelConstants.EXT_OFFSET] = ext;
+  }
+
   private _resetBlinkingRowState(): void {
     this._rowHasBlinkingCells = new Array(this._terminal.rows).fill(false);
     this._rowHasBlinkingCellsCount = 0;

bin/esbuild_all.mjs

@@ -19,14 +19,17 @@ for (const addon of addons) {
 // Demo job - This requires the others to be built so it's not included when building all
 // jobs.push(createJob('demo-client', [`--demo-client`]));
 
-await Promise.all(jobs.map((job, i) => {
+const codes = await Promise.all(jobs.map(job => {
   return new Promise(r => {
     job.cp.on('exit', code => {
       log(`Finished \x1b[32m${job.name}\x1b[0m${code ? ' \x1b[31mwith errors\x1b[0m' : ''}`);
-      r(code);
+      r(code ?? 1);
     });
   });
 }));
+if (codes.some(code => code !== 0)) {
+  process.exit(1);
+}
 
 /**
  * @param {string} message

bin/setup-full.mjs

@@ -5,7 +5,7 @@ import { spawnSync } from 'node:child_process';
 import { basename, dirname, resolve, sep } from 'node:path';
 import { fileURLToPath } from 'node:url';
 
-const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '../..');
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
 const nodeModulesPath = resolve(repoRoot, 'node_modules');
 const npmExecutable = process.platform === 'win32' ? 'npm.cmd' : 'npm';
 
@@ -13,7 +13,7 @@ const npmExecutable = process.platform === 'win32' ? 'npm.cmd' : 'npm';
 
 /** @param {string} message */
 function log(message) {
-  console.info(`[setup-fast] ${message}`);
+  console.info(`[setup-full] ${message}`);
 }
 
 /** @param {string[]} args */

bin/test_integration.js

@@ -12,7 +12,7 @@ let argv = process.argv.slice(2);
 let suiteFilter = undefined;
 while (argv.some(e => e.startsWith('--suite='))) {
   const i = argv.findIndex(e => e.startsWith('--suite='));
-  const match = argv[i].match(/--suite=(?<suitename>.+)/)
+  const match = argv[i].match(/--suite=(?<suitename>.+)/);
   suiteFilter = match?.groups?.suitename ?? undefined;
   argv.splice(i, 1);
 }
@@ -42,12 +42,18 @@ if (suiteFilter) {
   configs = configs.filter(e => e.name === suiteFilter);
 }
 
+if (suiteFilter && configs.length === 0) {
+  console.error(`Unknown suite: ${suiteFilter}`);
+  process.exit(1);
+}
+
 function npmBinScript(script) {
   return path.resolve(__dirname, `../node_modules/.bin/` + (process.platform === 'win32' ?
     `${script}.cmd` : script));
 }
 
 async function run() {
+  let exitCode = 0;
   for (const config of configs) {
     const command = npmBinScript('playwright');
     const args = ['test', '-c', config.path, ...argv];
@@ -62,10 +68,13 @@ async function run() {
 
     if (run.error) {
       console.error(run.error);
-      process.exit(run.status ?? -1);
+      process.exit(run.status ?? 1);
     }
 
-    process.exit(run.status);
+    if (run.status) {
+      exitCode = run.status;
+    }
   }
+  process.exit(exitCode);
 }
 run();

bin/test_mousemodes.js

@@ -177,7 +177,7 @@ const ENC = {
 }
 
 function printMenu() {
-  console.log('\x1b[2J\x1b\[HTest mouse reports [Ctrl-C to exit]');
+  console.log('\x1b[2J\x1b[HTest mouse reports [Ctrl-C to exit]');
   console.log();
   console.log('  Selected protocol [Ctrl-A to switch]');
   const protocols = Object.keys(PROTOCOLS);

bin/test_unit.js

@@ -21,7 +21,7 @@ if (process.argv.length > 2) {
   flagArgs = args.filter(e => e.startsWith('--'));
   // ability to inject particular test files via
   // npm run test [testFileA testFileB ...]
-  files = args.filter(e => !e.startsWith('--'));
+  const files = args.filter(e => !e.startsWith('--'));
   if (files.length) {
     testFiles = files;
   }
@@ -39,8 +39,6 @@ if (checkCoverage) {
     ...testFiles,
     ...flagArgs
   ];
-  console.info('executable', executable);
-  console.info('args', args);
   const run = cp.spawnSync(
     executable,
     args,
@@ -51,7 +49,7 @@ if (checkCoverage) {
       stdio: 'inherit'
     }
   );
-  process.exit(run.status);
+  process.exit(run.status ?? -1);
 }
 
 const run = cp.spawnSync(

demo/client/components/window/webglWindow.ts

@@ -11,8 +11,33 @@ export class WebglWindow extends BaseWindow implements IControlWindow {
   public readonly label = 'webgl';
 
   private _textureAtlasContainer!: HTMLElement;
+  private _stressRunning = false;
+  private _stressScrolling: HTMLInputElement | undefined;
 
   public build(container: HTMLElement): void {
+    const stressDiv = document.createElement('div');
+    const stressStart = document.createElement('button');
+    stressStart.id = 'stress-start';
+    stressStart.textContent = 'atlas stress start';
+    stressStart.addEventListener('click', () => this._stress());
+    stressDiv.appendChild(stressStart);
+
+    const stressStop = document.createElement('button');
+    stressStop.id = 'stress-stop';
+    stressStop.textContent = 'atlas stress stop';
+    stressStop.addEventListener('click', () => this._stressRunning = false);
+    stressDiv.appendChild(stressStop);
+
+    this._stressScrolling = document.createElement('input');
+    this._stressScrolling.type = 'checkbox';
+    this._stressScrolling.id = 'stress-scrolling';
+    stressDiv.appendChild(this._stressScrolling);
+    const stressScrollingLabel = document.createElement('label');
+    stressScrollingLabel.htmlFor = 'stress-scrolling';
+    stressScrollingLabel.textContent = 'stress scrolling';
+    stressDiv.appendChild(stressScrollingLabel);
+    container.appendChild(stressDiv);
+
     const zoomCheckbox = document.createElement('input');
     zoomCheckbox.type = 'checkbox';
     zoomCheckbox.id = 'texture-atlas-zoom';
@@ -48,4 +73,33 @@ export class WebglWindow extends BaseWindow implements IControlWindow {
     canvas.style.width = `${canvas.width / dpr}px`;
     canvas.style.height = `${canvas.height / dpr}px`;
   }
+
+  private async _stress(): Promise<void> {
+    const TEXT = '!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~';
+    if (this._stressRunning) {
+      return;
+    }
+    this._stressRunning = true;
+    const scrolling = !!(this._stressScrolling?.checked);
+    for (let r = 0; r < 256; r += 2) {
+      for (let g = 0; g < 256; g += 2) {
+        let s: string[] = [];
+        for (let b = 0; b < 256; b += 2) {
+          if (!this._stressRunning) {
+            return;
+          }
+          const rbg = `RGB: ${[r, g, b]}`;
+          s.push(`\r\x1b[38;2;${r};${g};${b}m${rbg.padEnd(18, ' ')}${TEXT}`);
+          if (s.length >= 16) {
+            if (scrolling) {
+              await new Promise<void>(r => this._terminal.write(s.join('\r\n') + '\r\n', r));
+            } else {
+              await new Promise<void>(r => this._terminal.write('\x1b[H' + s.join('\r\n'), r));
+            }
+            s = [];
+          }
+        }
+      }
+    }
+  }
 }

package-lock.json

@@ -6689,16 +6689,6 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
-    "node_modules/randombytes": {
-      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/randombytes/-/randombytes-2.1.0.tgz",
-      "integrity": "sha512-vYl3iOX+4CKUWuxGi9Ukhie6fsqXqS9FE2Zaic4tNFD2N2QQaXOMFbuKK4QmDHC0JO6B1Zp41J0LpT0oR68amQ==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "safe-buffer": "^5.1.0"
-      }
-    },
     "node_modules/range-parser": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/range-parser/-/range-parser-1.2.1.tgz",
@@ -6932,27 +6922,6 @@
         "tslib": "^2.1.0"
       }
     },
-    "node_modules/safe-buffer": {
-      "version": "5.2.1",
-      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
-      "integrity": "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==",
-      "dev": true,
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/feross"
-        },
-        {
-          "type": "patreon",
-          "url": "https://www.patreon.com/feross"
-        },
-        {
-          "type": "consulting",
-          "url": "https://feross.org/support"
-        }
-      ],
-      "license": "MIT"
-    },
     "node_modules/safer-buffer": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
@@ -7078,13 +7047,13 @@
       }
     },
     "node_modules/serialize-javascript": {
-      "version": "6.0.2",
+      "version": "7.0.5",
-      "resolved": "https://registry.npmjs.org/serialize-javascript/-/serialize-javascript-6.0.2.tgz",
+      "resolved": "https://registry.npmjs.org/serialize-javascript/-/serialize-javascript-7.0.5.tgz",
-      "integrity": "sha512-Saa1xPByTTq2gdeFZYLLo+RFE35NHZkAbqZeWNd3BpzppeVisAqpDjcp8dyf6uIvEqJRd46jemmyA4iFIeVk8g==",
+      "integrity": "sha512-F4LcB0UqUl1zErq+1nYEEzSHJnIwb3AF2XWB94b+afhrekOUijwooAYqFyRbjYkm2PAKBabx6oYv/xDxNi8IBw==",
       "dev": true,
       "license": "BSD-3-Clause",
-      "dependencies": {
+      "engines": {
-        "randombytes": "^2.1.0"
+        "node": ">=20.0.0"
       }
     },
     "node_modules/serve-static": {

package.json

@@ -11,6 +11,9 @@
   "workspaces": [
     "addons/*"
   ],
+  "overrides": {
+    "serialize-javascript": "^7.0.3"
+  },
   "keywords": [
     "cli",
     "command-line",
@@ -61,9 +64,9 @@
     "test-integration-firefox": "node ./bin/test_integration.js --workers=75% \"--project=FirefoxStable\"",
     "test-integration-webkit": "node ./bin/test_integration.js --workers=75% \"--project=WebKit\"",
     "test-integration-debug": "node ./bin/test_integration.js  --workers=1 --headed --timeout=30000",
-    "benchmark": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json",
+    "benchmark": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json",
-    "benchmark-baseline": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json --baseline out-test/benchmark/*benchmark.js",
+    "benchmark-baseline": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json --baseline out-test/benchmark/*benchmark.js",
-    "benchmark-eval": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json --eval out-test/benchmark/*benchmark.js",
+    "benchmark-eval": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json --eval out-test/benchmark/*benchmark.js",
     "clean": "rm -rf lib out addons/*/lib addons/*/out",
     "vtfeatures": "node bin/extract_vtfeatures.js src/*/*.ts src/*/*/*.ts src/*.ts addons/**/src/*.ts",
     "prepackage": "npm run build",

src/browser/CoreBrowserTerminal.ts

@@ -505,7 +505,7 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
       this.textarea,
       parent.ownerDocument.defaultView ?? window,
       // Force unsafe null in node.js environment for tests
-      this._document ?? (typeof window !== 'undefined') ? window.document : null as any
+      this._document ?? ((typeof window !== 'undefined') ? window.document : null as any)
     ));
     this._instantiationService.setService(ICoreBrowserService, this._coreBrowserService);
 
@@ -1072,10 +1072,6 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
    * Clear the entire buffer, making the prompt line the new first line.
    */
   public clear(): void {
-    if (this.buffer.ybase === 0 && this.buffer.y === 0) {
-      // Don't clear if it's already clear
-      return;
-    }
     this.buffer.clearAllMarkers();
     this.buffer.lines.set(0, this.buffer.lines.get(this.buffer.ybase + this.buffer.y)!);
     this.buffer.lines.length = 1;

src/browser/RenderDebouncer.ts

@@ -23,7 +23,7 @@ export class RenderDebouncer implements IRenderDebouncerWithCallback {
   }
 
   public dispose(): void {
-    if (this._animationFrame) {
+    if (this._animationFrame !== undefined) {
       this._coreBrowserService.window.cancelAnimationFrame(this._animationFrame);
       this._animationFrame = undefined;
     }
@@ -31,9 +31,7 @@ export class RenderDebouncer implements IRenderDebouncerWithCallback {
 
   public addRefreshCallback(callback: FrameRequestCallback): number {
     this._refreshCallbacks.push(callback);
-    if (!this._animationFrame) {
+    this._animationFrame ??= this._coreBrowserService.window.requestAnimationFrame(() => this._innerRefresh());
-      this._animationFrame = this._coreBrowserService.window.requestAnimationFrame(() => this._innerRefresh());
-    }
     return this._animationFrame;
   }
 
@@ -46,7 +44,7 @@ export class RenderDebouncer implements IRenderDebouncerWithCallback {
     this._rowStart = this._rowStart !== undefined ? Math.min(this._rowStart, rowStart) : rowStart;
     this._rowEnd = this._rowEnd !== undefined ? Math.max(this._rowEnd, rowEnd) : rowEnd;
 
-    if (this._animationFrame) {
+    if (this._animationFrame !== undefined) {
       return;
     }
 

src/browser/TimeBasedDebouncer.ts

@@ -3,10 +3,10 @@
  * @license MIT
  */
 
-const RENDER_DEBOUNCE_THRESHOLD_MS = 1000; // 1 Second
-
 import { IRenderDebouncer } from './Types';
 
+const RENDER_DEBOUNCE_THRESHOLD_MS = 1000; // 1 Second
+
 /**
  * Debounces calls to update screen readers to update at most once configurable interval of time.
  */
@@ -31,7 +31,9 @@ export class TimeBasedDebouncer implements IRenderDebouncer {
   public dispose(): void {
     if (this._refreshTimeoutID) {
       clearTimeout(this._refreshTimeoutID);
+      this._refreshTimeoutID = undefined;
     }
+    this._additionalRefreshRequested = false;
   }
 
   public refresh(rowStart: number | undefined, rowEnd: number | undefined, rowCount: number): void {
@@ -48,6 +50,11 @@ export class TimeBasedDebouncer implements IRenderDebouncer {
     const refreshRequestTime: number = performance.now();
     if (refreshRequestTime - this._lastRefreshMs >= this._debounceThresholdMS) {
       // Enough time has elapsed since the last refresh; refresh immediately
+      if (this._refreshTimeoutID !== undefined) {
+        clearTimeout(this._refreshTimeoutID);
+        this._refreshTimeoutID = undefined;
+        this._additionalRefreshRequested = false;
+      }
       this._lastRefreshMs = refreshRequestTime;
       this._innerRefresh();
     } else if (!this._additionalRefreshRequested) {

src/browser/input/Mouse.ts

@@ -37,10 +37,6 @@ export function getCoords(window: Pick<Window, 'getComputedStyle'>, event: Pick<
   }
 
   const coords = getCoordsRelativeToElement(window, event, element);
-  if (!coords) {
-    return undefined;
-  }
-
   coords[0] = Math.ceil((coords[0] + (isSelection ? cssCellWidth / 2 : 0)) / cssCellWidth);
   coords[1] = Math.ceil(coords[1] / cssCellHeight);
 

src/browser/input/MoveToCell.ts

@@ -156,7 +156,7 @@ function wrappedRowsForRow(currentRow: number, bufferService: IBufferService): n
  */
 function horizontalDirection(startX: number, startY: number, targetX: number, targetY: number, bufferService: IBufferService, applicationCursor: boolean): Direction {
   let startRow;
-  if (moveToRequestedRow(targetX, targetY, bufferService, applicationCursor).length > 0) {
+  if (moveToRequestedRow(startY, targetY, bufferService, applicationCursor).length > 0) {
     startRow = targetY - wrappedRowsForRow(targetY, bufferService);
   } else {
     startRow = startY;

src/browser/renderer/dom/DomRenderer.ts

@@ -33,7 +33,7 @@ let nextTerminalId = 1;
 
 /**
  * The standard renderer and fallback for when the webgl addon is slow. This is not meant to be
- * particularly fast and will even lack some features such as custom glyphs, however this is more
+ * particularly fast and will even lack some features such as custom glyphs, hoever this is more
  * reliable as webgl may not work on some machines.
  */
 export class DomRenderer extends Disposable implements IRenderer {
@@ -430,7 +430,7 @@ export class DomRenderer extends Disposable implements IRenderer {
         documentFragment.appendChild(this._createSelectionElement(viewportCappedStartRow + 1, 0, this._bufferService.cols, middleRowsCount));
         // Draw final row
         if (viewportCappedStartRow !== viewportCappedEndRow) {
-          // Only draw viewportEndRow if it's not the same as viewportStartRow
+          // Only draw viewportEndRow if it's not the same as viewporttartRow
           const finalEndCol = viewportEndRow === viewportCappedEndRow ? end[0] : this._bufferService.cols;
           documentFragment.appendChild(this._createSelectionElement(viewportCappedEndRow, 0, finalEndCol));
         }
@@ -536,9 +536,14 @@ export class DomRenderer extends Disposable implements IRenderer {
     for (let y = start; y <= end; y++) {
       const row = y + buffer.ydisp;
       const rowElement = this._rowElements[y];
+      if (!rowElement) {
+        continue;
+      }
       const lineData = buffer.lines.get(row);
-      if (!rowElement || !lineData) {
+      if (!lineData) {
-        break;
+        rowElement.replaceChildren();
+        this._setRowBlinkState(y, false);
+        continue;
       }
       rowElement.replaceChildren(
         ...this._rowFactory.createRow(
@@ -610,9 +615,14 @@ export class DomRenderer extends Disposable implements IRenderer {
     for (let i = y; i <= y2; ++i) {
       const row = i + buffer.ydisp;
       const rowElement = this._rowElements[i];
+      if (!rowElement) {
+        continue;
+      }
       const bufferline = buffer.lines.get(row);
-      if (!rowElement || !bufferline) {
+      if (!bufferline) {
-        break;
+        rowElement.replaceChildren();
+        this._setRowBlinkState(i, false);
+        continue;
       }
       rowElement.replaceChildren(
         ...this._rowFactory.createRow(
@@ -694,7 +704,7 @@ class CursorBlinkStateManager {
   }
 
   private _clearIdleTimer(): void {
-    if (this._idleTimeout) {
+    if (this._idleTimeout !== undefined) {
       this._coreBrowserService.window.clearTimeout(this._idleTimeout);
       this._idleTimeout = undefined;
     }

src/browser/renderer/dom/DomRendererRowFactory.ts

@@ -380,7 +380,7 @@ export class DomRendererRowFactory {
       if (!isTop && isInSelection) {
         // If in the selection, force the element to be above the selection to improve contrast and
         // support opaque selections. The applies background is not actually needed here as
-        // selection is drawn in a separate container; the main purpose of this is to ensure minimum
+        // selection is drawn in a seperate container, the main purpose of this to ensuring minimum
         // contrast ratio
         bgOverride = this._coreBrowserService.isFocused ? colors.selectionBackgroundOpaque : colors.selectionInactiveBackgroundOpaque;
         bg = bgOverride.rgba >> 8 & 0xFFFFFF;

src/browser/selection/SelectionModel.test.ts

@@ -64,6 +64,13 @@ describe('SelectionModel', () => {
       assert.deepEqual(model.finalSelectionStart, undefined);
       assert.deepEqual(model.finalSelectionEnd, undefined);
     });
+    it('should reset selection start to origin when start row is trimmed', () => {
+      model.selectionStart = [50, 0];
+      model.selectionEnd = [10, 2];
+      assert.equal(model.handleTrim(1), true);
+      assert.deepEqual(model.finalSelectionStart, [0, 0]);
+      assert.deepEqual(model.finalSelectionEnd, [10, 1]);
+    });
   });
 
   describe('finalSelectionStart', () => {

src/browser/selection/SelectionModel.ts

@@ -88,7 +88,7 @@ export class SelectionModel {
       return [startPlusLength, this.selectionStart[1]];
     }
 
-    // Ensure the word/line is selected after a double/triple click
+    // Ensure the the word/line is selected after a double/triple click
     if (this.selectionStartLength) {
       // Select the larger of the two when start and end are on the same line
       if (this.selectionEnd[1] === this.selectionStart[1]) {
@@ -135,9 +135,10 @@ export class SelectionModel {
       return true;
     }
 
-    // If the selection start is trimmed, ensure the start column is 0.
+    // If the selection start row is trimmed away, reset to the buffer origin.
     if (this.selectionStart && this.selectionStart[1] < 0) {
-      this.selectionStart[1] = 0;
+      this.selectionStart = [0, 0];
+      return true;
     }
     return false;
   }

src/browser/services/CharacterJoinerService.ts

@@ -100,6 +100,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
 
     const ranges: [number, number][] = [];
     const lineStr = line.translateToString(true);
+    const trimmedLength = line.getTrimmedLength();
 
     // Because some cells can be represented by multiple javascript characters,
     // we track the cell and the string indexes separately. This allows us to
@@ -111,7 +112,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     let rangeAttrFG = line.getFg(0);
     let rangeAttrBG = line.getBg(0);
 
-    for (let x = 0; x < line.getTrimmedLength(); x++) {
+    for (let x = 0; x < trimmedLength; x++) {
       line.loadCell(x, this._workCell);
 
       if (this._workCell.getWidth() === 0) {
@@ -147,7 +148,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     }
 
     // Process any trailing ranges.
-    if (this._bufferService.cols - rangeStartColumn > 1) {
+    if (trimmedLength - rangeStartColumn > 1) {
       const joinedRanges = this._getJoinedRanges(
         lineStr,
         rangeStartStringIndex,
@@ -216,7 +217,8 @@ export class CharacterJoinerService implements ICharacterJoinerService {
       return;
     }
 
-    for (let x = startCol; x < this._bufferService.cols; x++) {
+    const trimmedLength = line.getTrimmedLength();
+    for (let x = startCol; x < trimmedLength; x++) {
       const width = line.getWidth(x);
       const length = line.getString(x).length || WHITESPACE_CELL_CHAR.length;
 
@@ -264,7 +266,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     // If there is still a range left at the end, it must extend all the way to
     // the end of the line.
     if (currentRange) {
-      currentRange[1] = this._bufferService.cols;
+      currentRange[1] = trimmedLength;
     }
   }
 

src/browser/services/SelectionService.ts

@@ -704,7 +704,7 @@ export class SelectionService extends Disposable implements ISelectionService {
         if (this._activeSelectionMode !== SelectionMode.COLUMN) {
           this._model.selectionEnd[0] = this._bufferService.cols;
         }
-        this._model.selectionEnd[1] = Math.min(buffer.ydisp + this._bufferService.rows, buffer.lines.length - 1);
+        this._model.selectionEnd[1] = Math.min(buffer.ydisp + this._bufferService.rows - 1, buffer.lines.length - 1);
       } else {
         if (this._activeSelectionMode !== SelectionMode.COLUMN) {
           this._model.selectionEnd[0] = 0;
@@ -927,7 +927,7 @@ export class SelectionService extends Disposable implements ISelectionService {
     // Incremenet the end index so it is at the start of the next character
     endIndex++;
 
-    // Calculate the start _column_, converting the string indexes back to
+    // Calculate the start _column_, converting the the string indexes back to
     // column coordinates.
     let start =
       startIndex // The index of the selection's start char in the line string
@@ -935,7 +935,7 @@ export class SelectionService extends Disposable implements ISelectionService {
       - leftWideCharCount // The number of wide chars left of the initial char
       + leftLongCharOffset; // The number of additional chars left of the initial char added by columns with strings longer than 1 (emojis)
 
-    // Calculate the length in _columns_, converting the string indexes back
+    // Calculate the length in _columns_, converting the the string indexes back
     // to column coordinates.
     let length = Math.min(this._bufferService.cols, // Disallow lengths larger than the terminal cols
       endIndex // The index of the selection's end char in the line string

src/common/InputHandler.test.ts

@@ -16,8 +16,10 @@ import { MockCoreService, MockBufferService, MockOptionsService, MockLogService,
 import { IBufferService, ICoreService, type IOscLinkService } from './services/Services';
 import { DEFAULT_OPTIONS } from './services/OptionsService';
 import { BufferService } from './services/BufferService';
+import { CharsetService } from './services/CharsetService';
 import { CoreService } from './services/CoreService';
 import { OscLinkService } from './services/OscLinkService';
+import { CHARSETS } from './data/Charsets';
 
 
 function getCursor(bufferService: IBufferService): number[] {
@@ -639,19 +641,38 @@ describe('InputHandler', () => {
   });
   describe('print', () => {
     it('should not cause an infinite loop (regression test)', () => {
-      const inputHandler = new TestInputHandler(
-        new MockBufferService(80, 30),
-        new MockCharsetService(),
-        new MockCoreService(),
-        new MockLogService(),
-        new MockOptionsService(),
-        new MockOscLinkService(),
-        new MockMouseStateService(),
-        new MockUnicodeService()
-      );
       const container = new Uint32Array(10);
       container[0] = 0x200B;
+      const lineCountBefore = bufferService.buffer.lines.length;
       inputHandler.print(container, 0, 1);
+      assert.strictEqual(bufferService.buffer.y, 0);
+      assert.strictEqual(bufferService.buffer.lines.length, lineCountBefore);
+    });
+    it('should join combining characters in a single print', async () => {
+      await inputHandler.parseP('e\u0301');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301');
+      assert.strictEqual(bufferService.buffer.x, 1);
+    });
+    it('should join combining characters split across parse calls', async () => {
+      await inputHandler.parseP('e');
+      await inputHandler.parseP('\u0301');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301');
+      assert.strictEqual(bufferService.buffer.x, 1);
+    });
+    it('should repeat preceding grapheme cluster via REP', async () => {
+      await inputHandler.parseP('e\u0301\x1b[2b');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301e\u0301e\u0301');
+      assert.strictEqual(bufferService.buffer.x, 3);
+    });
+    it('should not repeat when REP has no preceding join state', async () => {
+      await inputHandler.parseP('\x1b[2b');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '');
+      assert.strictEqual(bufferService.buffer.x, 0);
+    });
+    it('should not repeat after an intervening escape sequence', async () => {
+      await inputHandler.parseP('a\x1b[0m\x1b[2b');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'a');
+      assert.strictEqual(bufferService.buffer.x, 1);
     });
     it('should clear cells to the right on early wrap-around', async () => {
       bufferService.resize(5, 5);
@@ -668,6 +689,49 @@ describe('InputHandler', () => {
     });
   });
 
+  describe('ISO-2022 character sets', () => {
+    let charsetService: CharsetService;
+
+    beforeEach(() => {
+      charsetService = new CharsetService();
+      inputHandler = new TestInputHandler(
+        bufferService,
+        charsetService,
+        coreService,
+        new MockLogService(),
+        optionsService,
+        oscLinkService,
+        new MockMouseStateService(),
+        new MockUnicodeService()
+      );
+    });
+
+    it('should map G0 line drawing via ESC ( 0', async () => {
+      await inputHandler.parseP('\x1b(0q\x1b(Bq');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500q');
+    });
+
+    it('should map G1 line drawing after ESC ) 0 and SO', async () => {
+      await inputHandler.parseP('\x1b)0\x0eq\x0f\x1b(Bq');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500q');
+    });
+
+    it('should restore charset and glevel on ESC 7 / ESC 8', async () => {
+      await inputHandler.parseP('\x1b)0\x0e');
+      assert.strictEqual(charsetService.glevel, 1);
+      assert.strictEqual(charsetService.charset, CHARSETS['0']);
+      await inputHandler.parseP('\x1b7');
+      await inputHandler.parseP('\x0f\x1b(B');
+      assert.strictEqual(charsetService.glevel, 0);
+      assert.ok(charsetService.charset === undefined);
+      await inputHandler.parseP('\x1b8');
+      assert.strictEqual(charsetService.glevel, 1);
+      assert.strictEqual(charsetService.charset, CHARSETS['0']);
+      await inputHandler.parseP('q');
+      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500');
+    });
+  });
+
   describe('alt screen', () => {
     let bufferService: IBufferService;
     let handler: TestInputHandler;
@@ -1182,6 +1246,19 @@ describe('InputHandler', () => {
       await inputHandler.parseP('\x1b[100;100H');
       assert.deepEqual(getCursor(bufferService), [9, 9]);
     });
+    it('cursor position (CUP) with DECOM and scroll margins', async () => {
+      await inputHandler.parseP('\x1b[?6h\x1b[2;3r\x1b[1;1H');
+      assert.deepEqual(getCursor(bufferService), [0, 1]);
+      await inputHandler.parseP('X');
+      assert.strictEqual(getLines(bufferService, 3)[1], 'X');
+      await inputHandler.parseP('\x1b[2;1H');
+      assert.deepEqual(getCursor(bufferService), [0, 2]);
+      await inputHandler.parseP('\x1b[10;10H');
+      assert.deepEqual(getCursor(bufferService), [9, 2]);
+      await inputHandler.parseP('\x1b[?6l');
+      await inputHandler.parseP('\x1b[2;1H');
+      assert.deepEqual(getCursor(bufferService), [0, 1]);
+    });
     it('horizontal position absolute (HPA)', async () => {
       await inputHandler.parseP('\x1b[`');
       assert.deepEqual(getCursor(bufferService), [0, 0]);

src/common/InputHandler.ts

@@ -273,7 +273,7 @@ export class InputHandler extends Disposable implements IInputHandler {
     this._parser.setExecuteHandler(C0.HT, () => this.tab());
     this._parser.setExecuteHandler(C0.SO, () => this.shiftOut());
     this._parser.setExecuteHandler(C0.SI, () => this.shiftIn());
-    // FIXME:   What to do with missing? Old code just added those to print.
+    // FIXME:   What do to with missing? Old code just added those to print.
 
     this._parser.setExecuteHandler(C1.IND, () => this.index());
     this._parser.setExecuteHandler(C1.NEL, () => this.nextLine());
@@ -550,7 +550,7 @@ export class InputHandler extends Disposable implements IInputHandler {
 
       // get charset replacement character
       // charset is only defined for ASCII, therefore we only
-      // search for a replacement char if code < 127
+      // search for an replacement char if code < 127
       if (code < 127 && charset) {
         const ch = charset[String.fromCharCode(code)];
         if (ch) {

src/common/Types.ts

@@ -234,9 +234,9 @@ export interface ICoreMouseProtocol {
 /**
  * CoreMouseEncoding
  * The tracking encoding can be registered and activated at the MouseStateService.
- * If a ICoreMouseEvent passes all protocol restrictions it will be encoded
+ * If a ICoreMouseEvent passes all procotol restrictions it will be encoded
  * with the active encoding and sent out.
- * Note: Returning an empty string will suppress sending a mouse report,
+ * Note: Returning an empty string will supress sending a mouse report,
  * which can be used to skip creating falsey reports in limited encodings
  * (DEFAULT only supports up to 223 1-based as coord value).
  */

src/common/WindowsMode.test.ts

@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { DEFAULT_ATTR_DATA } from './buffer/BufferLine';
+import { updateWindowsModeWrappedState } from './WindowsMode';
+import { BufferService } from './services/BufferService';
+import { OptionsService } from './services/OptionsService';
+import { MockLogService } from './TestUtils.test';
+
+describe('WindowsMode', () => {
+  describe('updateWindowsModeWrappedState', () => {
+    it('should mark the next line wrapped when the previous line ends in a non-whitespace character', () => {
+      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
+      const buffer = bufferService.buffer;
+      const previousLine = buffer.lines.get(buffer.ybase)!;
+      for (let i = 0; i < bufferService.cols; i++) {
+        previousLine!.setCellFromCodepoint(i, 'a'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+      }
+      buffer.y = 1;
+
+      updateWindowsModeWrappedState(bufferService);
+
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, true);
+    });
+
+    it('should not mark the next line wrapped when the previous line ends in whitespace', () => {
+      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
+      const buffer = bufferService.buffer;
+      const previousLine = buffer.lines.get(buffer.ybase)!;
+      for (let i = 0; i < bufferService.cols - 1; i++) {
+        previousLine!.setCellFromCodepoint(i, 'a'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+      }
+      previousLine!.setCellFromCodepoint(bufferService.cols - 1, ' '.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+      buffer.y = 1;
+
+      updateWindowsModeWrappedState(bufferService);
+
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, false);
+    });
+
+    it('should not mark the next line wrapped when the previous line ends in a null cell', () => {
+      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
+      const buffer = bufferService.buffer;
+      buffer.y = 1;
+
+      updateWindowsModeWrappedState(bufferService);
+
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, false);
+    });
+  });
+});

src/common/buffer/AttributeData.ts

@@ -204,7 +204,7 @@ export class ExtendedAttrs implements IExtendedAttrs {
 
   /**
    * Convenient method to indicate whether the object holds no additional information,
-   * that needs to be persistent in the buffer.
+   * that needs to be persistant in the buffer.
    */
   public isEmpty(): boolean {
     return this.underlineStyle === UnderlineStyle.NONE && this._urlId === 0;

src/common/buffer/Buffer.test.ts

@@ -233,6 +233,27 @@ describe('Buffer', () => {
           assert.equal(buffer.lines.length, INIT_ROWS + 10);
         });
       });
+
+      describe('Windows ConPTY', () => {
+        beforeEach(() => {
+          optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 19000 };
+        });
+
+        it('should not adjust ybase or ydisp when growing rows', () => {
+          buffer.fillViewportRows();
+          for (let i = 0; i < 10; i++) {
+            buffer.lines.push(buffer.getBlankLine(DEFAULT_ATTR_DATA));
+          }
+          buffer.y = INIT_ROWS - 1;
+          buffer.ybase = 10;
+          buffer.ydisp = 10;
+          const linesBefore = buffer.lines.length;
+          buffer.resize(INIT_COLS, INIT_ROWS + 5);
+          assert.equal(buffer.ybase, 10);
+          assert.equal(buffer.ydisp, 10);
+          assert.equal(buffer.lines.length, linesBefore + 5);
+        });
+      });
     });
 
     describe('row and column increased', () => {
@@ -305,6 +326,71 @@ describe('Buffer', () => {
         assert.equal(buffer.lines.get(8)!.translateToString(), '     ');
         assert.equal(buffer.lines.get(9)!.translateToString(), '     ');
       });
+      it('should gate reflow on ConPTY buildNumber 21376', () => {
+        const prepareWrappedShrink = () => {
+          buffer.fillViewportRows();
+          buffer.resize(5, 10);
+          const firstLine = buffer.lines.get(0)!;
+          for (let i = 0; i < 5; i++) {
+            const code = 'a'.charCodeAt(0) + i;
+            firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
+          }
+          buffer.y = 1;
+          buffer.resize(1, 10);
+        };
+
+        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21375 };
+        prepareWrappedShrink();
+        assert.equal(buffer.lines.get(1)!.translateToString().trim(), '');
+
+        buffer = new TestBuffer(true, optionsService, bufferService, new MockLogService());
+        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21376 };
+        prepareWrappedShrink();
+        assert.equal(buffer.lines.get(1)!.translateToString().trim(), 'b');
+        assert.ok(buffer.lines.get(1)!.isWrapped);
+      });
+      it('should unwrap lines on ConPTY builds with reflow support', () => {
+        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21376 };
+        buffer.fillViewportRows();
+        buffer.resize(5, 10);
+        const firstLine = buffer.lines.get(0)!;
+        for (let i = 0; i < 5; i++) {
+          const code = 'a'.charCodeAt(0) + i;
+          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
+        }
+        buffer.y = 1;
+        buffer.resize(1, 10);
+        buffer.resize(5, 10);
+        assert.equal(buffer.lines.get(0)!.translateToString(), 'abcde');
+        assert.equal(buffer.lines.get(1)!.translateToString(), '     ');
+      });
+      it('should reflow wrapped lines containing the cursor when reflowCursorLine is enabled', () => {
+        optionsService.options.reflowCursorLine = true;
+        buffer.fillViewportRows();
+        buffer.resize(5, 10);
+        const firstLine = buffer.lines.get(0)!;
+        for (let i = 0; i < 5; i++) {
+          const code = 'a'.charCodeAt(0) + i;
+          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
+        }
+        buffer.resize(1, 10);
+        buffer.y = 2;
+        buffer.resize(5, 10);
+        assert.equal(buffer.lines.get(0)!.translateToString(), 'abcde');
+      });
+      it('should not reflow wrapped lines containing the cursor by default', () => {
+        buffer.fillViewportRows();
+        buffer.resize(5, 10);
+        const firstLine = buffer.lines.get(0)!;
+        for (let i = 0; i < 5; i++) {
+          const code = 'a'.charCodeAt(0) + i;
+          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
+        }
+        buffer.resize(1, 10);
+        buffer.y = 2;
+        buffer.resize(5, 10);
+        assert.notEqual(buffer.lines.get(0)!.translateToString(), 'abcde');
+      });
       it('should discard parts of wrapped lines that go out of the scrollback', () => {
         buffer.fillViewportRows();
         optionsService.options.scrollback = 1;

src/common/buffer/Buffer.ts

@@ -578,7 +578,7 @@ export class Buffer extends Disposable implements IBuffer {
    * @param i The index to start setting up tab stops from.
    */
   public setupTabStops(i?: number): void {
-    if (i !== undefined) {
+    if (i !== null && i !== undefined) {
       if (!this.tabs[i]) {
         i = this.prevStop(i);
       }

src/common/buffer/BufferLine.ts

@@ -71,10 +71,20 @@ export interface IBufferLineStringCache {
  * (if only one particular value is needed) or `loadCell`. For `loadCell` in a loop
  * memory allocs / GC pressure can be greatly reduced by reusing the CellData object.
  */
+/**
+ * Shared empty sparse map for lines with no combining data.
+ * Uses a sentinel + copy-on-write so `copyFrom` can detect empty `_combined` with
+ * reference equality. `_extendedAttrs` uses `undefined` instead (addon-image writes
+ * the map directly without BufferLine APIs).
+ */
+const EMPTY_SPARSE_MAP: {[index: number]: string} = Object.create(null);
+
 export class BufferLine implements IBufferLine {
   protected _data: Uint32Array;
-  protected _combined: {[index: number]: string} = {};
+  /** Sparse cache; only read when `IS_COMBINED_MASK` is set in `_data`. */
-  protected _extendedAttrs: {[index: number]: IExtendedAttrs | undefined} = {};
+  protected _combined: {[index: number]: string} = EMPTY_SPARSE_MAP;
+  /** Sparse cache; only read when `HAS_EXTENDED` is set in `_data`. */
+  protected _extendedAttrs: {[index: number]: IExtendedAttrs | undefined} | undefined;
   protected _stringCacheEntryRef: WeakRef<IBufferLineStringCacheEntry> | undefined;
   public length: number;
 
@@ -119,6 +129,7 @@ export class BufferLine implements IBufferLine {
     this._invalidateStringCache();
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = value[CHAR_DATA_ATTR_INDEX];
     if (value[CHAR_DATA_CHAR_INDEX].length > 1) {
+      this._ensureCombinedMap();
       this._combined[index] = value[1];
       this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = index | Content.IS_COMBINED_MASK | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT);
     } else {
@@ -205,9 +216,15 @@ export class BufferLine implements IBufferLine {
     cell.bg = this._data[$startIndex + Cell.BG];
     if (cell.content & Content.IS_COMBINED_MASK) {
       cell.combinedData = this._combined[index];
+    } else {
+      cell.combinedData = '';
     }
     if (cell.bg & BgFlags.HAS_EXTENDED) {
-      cell.extended = this._extendedAttrs[index]!;
+      cell.extended = this._extendedAttrs![index]!;
+    } else {
+      // Do not mutate cell.extended in place: it may still reference this line's map entry from a
+      // prior loadCell into a reused CellData (e.g. $workCell during insert/delete).
+      cell.extended = DEFAULT_ATTR_DATA.extended.clone();
     }
     return cell;
   }
@@ -218,10 +235,11 @@ export class BufferLine implements IBufferLine {
   public setCell(index: number, cell: ICellData): void {
     this._invalidateStringCache();
     if (cell.content & Content.IS_COMBINED_MASK) {
+      this._ensureCombinedMap();
       this._combined[index] = cell.combinedData;
     }
     if (cell.bg & BgFlags.HAS_EXTENDED) {
-      this._extendedAttrs[index] = cell.extended;
+      this._ensureExtendedAttrsMap()[index] = cell.extended;
     }
     this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = cell.content;
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = cell.fg;
@@ -236,7 +254,7 @@ export class BufferLine implements IBufferLine {
   public setCellFromCodepoint(index: number, codePoint: number, width: number, attrs: IAttributeData): void {
     this._invalidateStringCache();
     if (attrs.bg & BgFlags.HAS_EXTENDED) {
-      this._extendedAttrs[index] = attrs.extended;
+      this._ensureExtendedAttrsMap()[index] = attrs.extended;
     }
     this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = codePoint | (width << Content.WIDTH_SHIFT);
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = attrs.fg;
@@ -254,12 +272,14 @@ export class BufferLine implements IBufferLine {
     let content = this._data[index * Constants.CELL_INDICIES + Cell.CONTENT];
     if (content & Content.IS_COMBINED_MASK) {
       // we already have a combined string, simply add
+      this._ensureCombinedMap();
       this._combined[index] += stringFromCodePoint(codePoint);
     } else {
       if (content & Content.CODEPOINT_MASK) {
         // normal case for combining chars:
         //  - move current leading char + new one into combined string
         //  - set combined flag
+        this._ensureCombinedMap();
         this._combined[index] = stringFromCodePoint(content & Content.CODEPOINT_MASK) + stringFromCodePoint(codePoint);
         content &= ~Content.CODEPOINT_MASK; // set codepoint in buffer to 0
         content |= Content.IS_COMBINED_MASK;
@@ -402,11 +422,13 @@ export class BufferLine implements IBufferLine {
         }
       }
       // remove any cut off extended attributes
-      const extKeys = Object.keys(this._extendedAttrs);
+      if (this._extendedAttrs) {
-      for (let i = 0; i < extKeys.length; i++) {
+        const extKeys = Object.keys(this._extendedAttrs);
-        const key = parseInt(extKeys[i], 10);
+        for (let i = 0; i < extKeys.length; i++) {
-        if (key >= cols) {
+          const key = parseInt(extKeys[i], 10);
-          delete this._extendedAttrs[key];
+          if (key >= cols) {
+            delete this._extendedAttrs[key];
+          }
         }
       }
     }
@@ -442,8 +464,8 @@ export class BufferLine implements IBufferLine {
       }
       return;
     }
-    this._combined = {};
+    this._combined = EMPTY_SPARSE_MAP;
-    this._extendedAttrs = {};
+    this._extendedAttrs = undefined;
     for (let i = 0; i < this.length; ++i) {
       this.setCell(i, fillCellData);
     }
@@ -459,14 +481,7 @@ export class BufferLine implements IBufferLine {
       this._data.set(line._data);
     }
     this.length = line.length;
-    this._combined = {};
+    this._copySparseMapsFrom(line);
-    for (const el in line._combined) {
-      this._combined[el] = line._combined[el];
-    }
-    this._extendedAttrs = {};
-    for (const el in line._extendedAttrs) {
-      this._extendedAttrs[el] = line._extendedAttrs[el];
-    }
     this.isWrapped = line.isWrapped;
   }
 
@@ -475,12 +490,7 @@ export class BufferLine implements IBufferLine {
     const newLine = new BufferLine(this._stringCache, 0, undefined, false);
     newLine._data = new Uint32Array(this._data);
     newLine.length = this.length;
-    for (const el in this._combined) {
+    newLine._copySparseMapsFrom(this);
-      newLine._combined[el] = this._combined[el];
-    }
-    for (const el in this._extendedAttrs) {
-      newLine._extendedAttrs[el] = this._extendedAttrs[el];
-    }
     newLine.isWrapped = this.isWrapped;
     return newLine;
   }
@@ -511,27 +521,14 @@ export class BufferLine implements IBufferLine {
         for (let i = 0; i < Constants.CELL_INDICIES; i++) {
           this._data[(destCol + cell) * Constants.CELL_INDICIES + i] = srcData[(srcCol + cell) * Constants.CELL_INDICIES + i];
         }
-        if (srcData[(srcCol + cell) * Constants.CELL_INDICIES + Cell.BG] & BgFlags.HAS_EXTENDED) {
+        this._copyCellMapsFrom(src, srcCol + cell, destCol + cell);
-          this._extendedAttrs[destCol + cell] = src._extendedAttrs[srcCol + cell];
-        }
       }
     } else {
       for (let cell = 0; cell < length; cell++) {
         for (let i = 0; i < Constants.CELL_INDICIES; i++) {
           this._data[(destCol + cell) * Constants.CELL_INDICIES + i] = srcData[(srcCol + cell) * Constants.CELL_INDICIES + i];
         }
-        if (srcData[(srcCol + cell) * Constants.CELL_INDICIES + Cell.BG] & BgFlags.HAS_EXTENDED) {
+        this._copyCellMapsFrom(src, srcCol + cell, destCol + cell);
-          this._extendedAttrs[destCol + cell] = src._extendedAttrs[srcCol + cell];
-        }
-      }
-    }
-
-    // Move any combined data over as needed, FIXME: repeat for extended attrs
-    const srcCombinedKeys = Object.keys(src._combined);
-    for (let i = 0; i < srcCombinedKeys.length; i++) {
-      const key = parseInt(srcCombinedKeys[i], 10);
-      if (key >= srcCol) {
-        this._combined[key - srcCol + destCol] = src._combined[key];
       }
     }
   }
@@ -620,4 +617,62 @@ export class BufferLine implements IBufferLine {
       cacheEntry.isTrimmed = false;
     }
   }
+
+  /** Copy sparse map entries for a single cell when `_data` flags require them. */
+  private _copyCellMapsFrom(src: BufferLine, srcCol: number, destCol: number): void {
+    const srcStart = srcCol * Constants.CELL_INDICIES;
+    if (src._data[srcStart + Cell.CONTENT] & Content.IS_COMBINED_MASK) {
+      this._ensureCombinedMap();
+      this._combined[destCol] = src._combined[srcCol];
+    }
+    if (src._data[srcStart + Cell.BG] & BgFlags.HAS_EXTENDED) {
+      this._ensureExtendedAttrsMap()[destCol] = src._extendedAttrs![srcCol]!;
+    }
+  }
+
+  /** Rebuild sparse maps from another line, keyed only by `_data` flags. */
+  private _copySparseMapsFrom(line: BufferLine): void {
+    const srcCombined = line._combined;
+    const srcExtended = line._extendedAttrs;
+
+    // Fast path: blank / scroll-recycle source (empty `_combined` sentinel, no extended map).
+    if (srcCombined === EMPTY_SPARSE_MAP && !srcExtended) {
+      this._combined = EMPTY_SPARSE_MAP;
+      this._extendedAttrs = undefined;
+      return;
+    }
+    this._copySparseMapsFromDense(line);
+  }
+
+  /** Copy sparse maps by scanning `_data` flags (inlined, no per-cell function calls). */
+  private _copySparseMapsFromDense(line: BufferLine): void {
+    this._combined = {};
+    this._extendedAttrs = {};
+    const srcData = line._data;
+    const srcCombined = line._combined;
+    const srcExtended = line._extendedAttrs;
+    const len = line.length;
+    const indices = Constants.CELL_INDICIES;
+    const combined = this._combined;
+    const extendedAttrs = this._extendedAttrs;
+    for (let i = 0; i < len; i++) {
+      const start = i * indices;
+      if (srcData[start + Cell.CONTENT] & Content.IS_COMBINED_MASK) {
+        combined[i] = srcCombined[i];
+      }
+      if (srcData[start + Cell.BG] & BgFlags.HAS_EXTENDED) {
+        extendedAttrs[i] = srcExtended![i];
+      }
+    }
+  }
+
+  private _ensureCombinedMap(): void {
+    if (this._combined === EMPTY_SPARSE_MAP) {
+      this._combined = {};
+    }
+  }
+
+  private _ensureExtendedAttrsMap(): {[index: number]: IExtendedAttrs | undefined} {
+    return this._extendedAttrs ??= {};
+  }
 }

src/common/buffer/BufferReflow.test.ts

@@ -3,10 +3,13 @@
  * @license MIT
  */
 import { assert } from 'chai';
+import { CircularList } from '../CircularList';
 import { BufferLine } from './BufferLine';
 import { BufferLineStringCache } from './BufferLineStringCache';
+import { CellData } from './CellData';
 import { NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE } from './Constants';
-import { reflowSmallerGetNewLineLengths } from './BufferReflow';
+import { reflowLargerGetLinesToRemove, reflowSmallerGetNewLineLengths } from './BufferReflow';
+import { IBufferLine } from './Types';
 
 const TEST_STRING_CACHE = new BufferLineStringCache();
 
@@ -93,4 +96,31 @@ describe('BufferReflow', () => {
       assert.deepEqual(reflowSmallerGetNewLineLengths([line], 4, 2), [2, 2], 'line: 汉, 语');
     });
   });
+  describe('reflowLargerGetLinesToRemove', () => {
+    const nullCell = CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
+
+    function createWrappedLines(chars: string): CircularList<IBufferLine> {
+      const lines = new CircularList<IBufferLine>(chars.length);
+      for (let i = 0; i < chars.length; i++) {
+        const line = new BufferLine(TEST_STRING_CACHE, 1);
+        line.set(0, [0, chars[i], 1, chars.charCodeAt(i)]);
+        line.isWrapped = i > 0;
+        lines.push(line);
+      }
+      return lines;
+    }
+
+    it('should skip reflow when the cursor is in a wrapped block and reflowCursorLine is false', () => {
+      const lines = createWrappedLines('abcde');
+      const skipped = reflowLargerGetLinesToRemove(lines, 1, 5, 2, nullCell, false);
+      const reflowed = reflowLargerGetLinesToRemove(lines, 1, 5, 2, nullCell, true);
+      assert.deepEqual(skipped, []);
+      assert.notDeepEqual(reflowed, []);
+    });
+
+    it('should reflow wrapped blocks when the cursor is outside the block', () => {
+      const lines = createWrappedLines('abcde');
+      assert.notDeepEqual(reflowLargerGetLinesToRemove(lines, 1, 5, 10, nullCell, false), []);
+    });
+  });
 });

src/common/buffer/BufferReflow.ts

@@ -13,7 +13,7 @@ export interface INewLayoutResult {
 }
 
 /**
- * Evaluates and returns indexes to be removed after reflowLarger occurs. Lines will be removed
+ * Evaluates and returns indexes to be removed after a reflow larger occurs. Lines will be removed
  * when a wrapped line unwraps.
  * @param lines The buffer lines.
  * @param oldCols The columns before resize
@@ -109,7 +109,7 @@ export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, o
 }
 
 /**
- * Creates and returns the new layout for lines given an array of indexes to be removed.
+ * Creates and return the new layout for lines given an array of indexes to be removed.
  * @param lines The buffer lines.
  * @param toRemove The indexes to remove.
  */

src/common/input/TextDecoder.test.ts

@@ -79,7 +79,7 @@ function assertDecodedRange(
   }
   const target = new Uint32Array(count);
   const length = decode(input, target);
-  assert.equal(length, count);
+  assert.strictEqual(length, count);
   let mismatchIndex = -1;
   let index = 0;
   for (let i = min; i < max; ++i) {
@@ -92,8 +92,8 @@ function assertDecodedRange(
     }
     index++;
   }
-  assert.equal(mismatchIndex, -1);
+  assert.strictEqual(mismatchIndex, -1);
-  assert.equal(outputToString(target, length), input);
+  assert.strictEqual(outputToString(target, length), input);
 }
 
 const BATCH_SIZE = 8192;
@@ -116,9 +116,9 @@ describe('text encodings', () => {
     const data = new Uint32Array(s.length);
     for (let i = 0; i < s.length; ++i) {
       data[i] = s.charCodeAt(i);
-      assert.equal(stringFromCodePoint(data[i]), s[i]);
+      assert.strictEqual(stringFromCodePoint(data[i]), s[i]);
     }
-    assert.equal(utf32ToString(data), s);
+    assert.strictEqual(utf32ToString(data), s);
   });
 
   describe('StringToUtf32 decoder', () => {
@@ -159,7 +159,7 @@ describe('text encodings', () => {
         const decoder = new StringToUtf32();
         const target = new Uint32Array(5);
         const length = decoder.decode(String.fromCharCode(0xFEFF), target);
-        assert.equal(length, 0);
+        assert.strictEqual(length, 0);
         decoder.clear();
       });
     });
@@ -169,7 +169,7 @@ describe('text encodings', () => {
       const target = new Uint32Array(500);
       for (let i = 0; i < TEST_STRINGS.length; ++i) {
         const length = decoder.decode(TEST_STRINGS[i], target);
-        assert.equal(toString(target, length), TEST_STRINGS[i]);
+        assert.strictEqual(toString(target, length), TEST_STRINGS[i]);
         decoder.clear();
       }
     });
@@ -184,7 +184,7 @@ describe('text encodings', () => {
           const written = decoder.decode(input[i], target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
     });
   });
@@ -226,7 +226,7 @@ describe('text encodings', () => {
         const target = new Uint32Array(5);
         const utf8Data = stringToUtf8Bytes(String.fromCharCode(0xFEFF));
         const length = decoder.decode(utf8Data, target);
-        assert.equal(length, 0);
+        assert.strictEqual(length, 0);
         decoder.clear();
       });
     });
@@ -237,7 +237,7 @@ describe('text encodings', () => {
       for (let i = 0; i < TEST_STRINGS.length; ++i) {
         const utf8Data = stringToUtf8Bytes(TEST_STRINGS[i]);
         const length = decoder.decode(utf8Data, target);
-        assert.equal(toString(target, length), TEST_STRINGS[i]);
+        assert.strictEqual(toString(target, length), TEST_STRINGS[i]);
         decoder.clear();
       }
     });
@@ -252,7 +252,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'ÄÖÜßöäü');
+        assert.strictEqual(decoded, 'ÄÖÜßöäü');
       });
 
       it('2/3 byte sequences - advance by 1', () => {
@@ -264,7 +264,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'Āր܀߀ö€ä€ü');
+        assert.strictEqual(decoded, 'Āր܀߀ö€ä€ü');
       });
 
       it('2/3/4 byte sequences - advance by 1', () => {
@@ -276,7 +276,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('2/3/4 byte sequences - advance by 2', () => {
@@ -288,7 +288,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 2), target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('2/3/4 byte sequences - advance by 3', () => {
@@ -300,7 +300,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 3), target);
           decoded += toString(target, written);
         }
-        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('BOMs (3 byte sequences) - advance by 2', () => {
@@ -312,7 +312,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 2), target);
           decoded += toString(target, written);
         }
-        assert.equal(decoded, '');
+        assert.strictEqual(decoded, '');
       });
 
       it('test break after 3 bytes - issue #2495', () => {
@@ -320,11 +320,37 @@ describe('text encodings', () => {
         const target = new Uint32Array(5);
         const utf8Data = fromByteString('\xf0\xa0\x9c\x8e');
         let written = decoder.decode(utf8Data.slice(0, 3), target);
-        assert.equal(written, 0);
+        assert.strictEqual(written, 0);
         written = decoder.decode(utf8Data.slice(3), target);
-        assert.equal(written, 1);
+        assert.strictEqual(written, 1);
-        assert(toString(target, written), '𠜎');
+        assert.strictEqual(toString(target, written), '𠜎');
       });
+
+      describe('0x80 not swallowed in continuation', () => {
+        it('A—B', () => {
+          const decoder = new Utf8ToUtf32();
+          const target = new Uint32Array(5);
+          const utf8Data = new TextEncoder().encode('A—BA—BA—BA—BA—B');
+          let decoded = '';
+          for (let i = 0; i < utf8Data.length; i += 2) {
+            const written = decoder.decode(utf8Data.slice(i, i + 2), target);
+            decoded += toString(target, written);
+          }
+          assert.strictEqual(decoded, 'A—BA—BA—BA—BA—B');
+        });
+        it('A𐀀B', () => {
+          const decoder = new Utf8ToUtf32();
+          const target = new Uint32Array(5);
+          const utf8Data = new TextEncoder().encode('A𐀀BA𐀀BA𐀀BA𐀀BA𐀀B');
+          let decoded = '';
+          for (let i = 0; i < utf8Data.length; i += 2) {
+            const written = decoder.decode(utf8Data.slice(i, i + 2), target);
+            decoded += toString(target, written);
+          }
+          assert.strictEqual(decoded, 'A𐀀BA𐀀BA𐀀BA𐀀BA𐀀B');
+        });
+      });
+
     });
   });
 });

src/common/input/TextDecoder.ts

@@ -158,9 +158,9 @@ export class Utf8ToUtf32 {
       cp &= ((((cp & 0xE0) === 0xC0)) ? 0x1F : (((cp & 0xF0) === 0xE0)) ? 0x0F : 0x07);
       let pos = 0;
       let tmp: number;
-      while ((tmp = this.interim[++pos] & 0x3F) && pos < 4) {
+      while ((tmp = this.interim[++pos]) && pos < 4) {
         cp <<= 6;
-        cp |= tmp;
+        cp |= tmp & 0x3F;
       }
       // missing bytes - read ahead from input
       const type = (((this.interim[0] & 0xE0) === 0xC0)) ? 2 : (((this.interim[0] & 0xF0) === 0xE0)) ? 3 : 4;

src/common/parser/ApcParser.test.ts

@@ -21,7 +21,7 @@ function identifier(id: IFunctionIdentifier): number {
       throw new Error('only one byte as prefix supported');
     }
     res = id.prefix.charCodeAt(0);
-    if (res && 0x3c > res || res > 0x3f) {
+    if (res < 0x3c || res > 0x3f) {
       throw new Error('prefix must be in range 0x3c .. 0x3f');
     }
   }
@@ -459,4 +459,29 @@ describe('ApcParser - async tests', () => {
       });
     });
   });
+  describe('reset', () => {
+    it('should abort active handlers with end(false) when reset during payload', () => {
+      const ident = identifier({ intermediates: '+', final: 'p' });
+      parser.registerHandler(ident, new TestHandler(reports, 'th'));
+      parser.start(ident);
+      let data = toUtf32('partial');
+      parser.put(data, 0, data.length);
+      parser.reset();
+      assert.deepEqual(reports, [
+        ['th', 'START'],
+        ['th', 'PUT', 'partial'],
+        ['th', 'END', false]
+      ]);
+      reports.length = 0;
+      parser.start(ident);
+      data = toUtf32('complete');
+      parser.put(data, 0, data.length);
+      parser.end(true);
+      assert.deepEqual(reports, [
+        ['th', 'START'],
+        ['th', 'PUT', 'complete'],
+        ['th', 'END', true]
+      ]);
+    });
+  });
 });

src/common/parser/DcsParser.test.ts

@@ -22,7 +22,7 @@ function identifier(id: IFunctionIdentifier): number {
       throw new Error('only one byte as prefix supported');
     }
     res = id.prefix.charCodeAt(0);
-    if (res && 0x3c > res || res > 0x3f) {
+    if (res < 0x3c || res > 0x3f) {
       throw new Error('prefix must be in range 0x3c .. 0x3f');
     }
   }
@@ -470,4 +470,30 @@ describe('DcsParser - async tests', () => {
       });
     });
   });
+  describe('reset', () => {
+    it('should abort active handlers with unhook(false) when reset during payload', () => {
+      const ident = identifier({ intermediates: '+', final: 'p' });
+      const params = Params.fromArray([1, 2, 3]);
+      parser.registerHandler(ident, new TestHandler(reports, 'th'));
+      parser.hook(ident, params);
+      let data = toUtf32('partial');
+      parser.put(data, 0, data.length);
+      parser.reset();
+      assert.deepEqual(reports, [
+        ['th', 'HOOK', [1, 2, 3]],
+        ['th', 'PUT', 'partial'],
+        ['th', 'UNHOOK', false]
+      ]);
+      reports.length = 0;
+      parser.hook(ident, params);
+      data = toUtf32('complete');
+      parser.put(data, 0, data.length);
+      parser.unhook(true);
+      assert.deepEqual(reports, [
+        ['th', 'HOOK', [1, 2, 3]],
+        ['th', 'PUT', 'complete'],
+        ['th', 'UNHOOK', true]
+      ]);
+    });
+  });
 });

src/common/parser/EscapeSequenceParser.test.ts

@@ -243,7 +243,7 @@ describe('EscapeSequenceParser', () => {
       p = new TestEscapeSequenceParser(tansitions);
       assert.deepEqual(p.transitions, tansitions);
     });
-    it('inital states', () => {
+    it('initial states', () => {
       assert.equal(parser.initialState, ParserState.GROUND);
       assert.equal(parser.currentState, ParserState.GROUND);
       assert.equal(parser.osc, '');
@@ -2177,6 +2177,38 @@ describe('EscapeSequenceParser - async', () => {
       parser.reset();
       await parseP(parser, INPUT); // does not throw anymore
     });
+    it('reset during async pause continues at next codepoint in chunk', async () => {
+      const localParser = new TestEscapeSequenceParser();
+      const localStack: any[] = [];
+      localParser.setPrintHandler((data, start, end) => {
+        let result = '';
+        for (let i = start; i < end; ++i) {
+          result += stringFromCodePoint(data[i]);
+        }
+        localStack.push(['PRINT', result]);
+      });
+      localParser.registerCsiHandler({ final: 'm' }, async params => {
+        localStack.push(['SGR', params.toArray()]);
+        return new Promise<boolean>(resolve => setTimeout(() => resolve(true), 0));
+      });
+      const data = '\x1b[1mXY';
+      const container = new Uint32Array(data.length);
+      const decoder = new StringToUtf32();
+      const len = decoder.decode(data, container);
+
+      assert.ok(localParser.parse(container, len) instanceof Promise);
+      localParser.reset();
+      assert.equal(localParser.parseStack.state, ParserStackType.RESET);
+
+      let prev: boolean | undefined = true;
+      let result: void | Promise<boolean> | undefined;
+      while (result = localParser.parse(container, len, prev)) {
+        prev = await result;
+      }
+
+      assert.deepEqual(localStack, [['SGR', [1]], ['PRINT', 'XY']]);
+      assert.equal(localParser.parseStack.state, ParserStackType.NONE);
+    });
     it('correct result on awaited parse call', async () => {
       await parseP(parser, INPUT);
       assert.deepEqual(callstack, RESULT);

src/common/parser/EscapeSequenceParser.ts

@@ -342,7 +342,7 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
         throw new Error('only one byte as prefix supported');
       }
       res = id.prefix.charCodeAt(0);
-      if (res && 0x3c > res || res > 0x3f) {
+      if (res < 0x3c || res > 0x3f) {
         throw new Error('prefix must be in range 0x3c .. 0x3f');
       }
     }

src/common/parser/OscParser.test.ts

@@ -464,4 +464,28 @@ describe('OscParser - async tests', () => {
       });
     });
   });
+  describe('reset', () => {
+    it('should abort active handlers with end(false) when reset during payload', () => {
+      parser.registerHandler(1234, new TestHandler(1234, reports, 'th'));
+      parser.start();
+      let data = toUtf32('1234;partial');
+      parser.put(data, 0, data.length);
+      parser.reset();
+      assert.deepEqual(reports, [
+        ['th', 1234, 'START'],
+        ['th', 1234, 'PUT', 'partial'],
+        ['th', 1234, 'END', false]
+      ]);
+      reports.length = 0;
+      parser.start();
+      data = toUtf32('1234;complete');
+      parser.put(data, 0, data.length);
+      parser.end(true);
+      assert.deepEqual(reports, [
+        ['th', 1234, 'START'],
+        ['th', 1234, 'PUT', 'complete'],
+        ['th', 1234, 'END', true]
+      ]);
+    });
+  });
 });

src/common/parser/Params.test.ts

@@ -199,13 +199,13 @@ describe('Params', () => {
     it('reject params lesser -1', () => {
       const params = new Params();
       params.addParam(-1);
-      assert.throws(() => params.addParam(-2), 'values lesser than -1 are not allowed');
+      assert.throws(() => params.addParam(-2), 'values less than -1 are not allowed');
     });
     it('reject subparams lesser -1', () => {
       const params = new Params();
       params.addParam(-1);
       params.addSubParam(-1);
-      assert.throws(() => params.addSubParam(-2), 'values lesser than -1 are not allowed');
+      assert.throws(() => params.addSubParam(-2), 'values less than -1 are not allowed');
       assert.deepEqual(params.toArray(), [-1, [-1]]);
     });
     it('clamp parsed params', () => {

src/common/parser/Params.ts

@@ -162,7 +162,7 @@ export class Params implements IParams {
       return;
     }
     if (value < -1) {
-      throw new Error('values lesser than -1 are not allowed');
+      throw new Error('values less than -1 are not allowed');
     }
     this._subParamsIdx[this.length] = this._subParamsLength << 8 | this._subParamsLength;
     this.params[this.length++] = value > Constants.MAX_VALUE ? Constants.MAX_VALUE : value;
@@ -185,7 +185,7 @@ export class Params implements IParams {
       return;
     }
     if (value < -1) {
-      throw new Error('values lesser than -1 are not allowed');
+      throw new Error('values less than -1 are not allowed');
     }
     this._subParams[this._subParamsLength++] = value > Constants.MAX_VALUE ? Constants.MAX_VALUE : value;
     this._subParamsIdx[this.length - 1]++;

src/common/services/BufferService.test.ts

@@ -0,0 +1,137 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { AttributeData } from '../buffer/AttributeData';
+import { BufferService } from './BufferService';
+import { OptionsService } from './OptionsService';
+import { MockLogService } from '../TestUtils.test';
+
+describe('BufferService', () => {
+  describe('scroll', () => {
+    const eraseAttr = new AttributeData();
+
+    it('should decrement ydisp when the buffer is full and the user has scrolled up', () => {
+      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+
+      while (!buffer.lines.isFull) {
+        bufferService.scroll(eraseAttr);
+      }
+      assert.strictEqual(buffer.lines.length, 5);
+
+      bufferService.isUserScrolling = true;
+      buffer.ydisp = 2;
+      const ybaseBefore = buffer.ybase;
+
+      bufferService.scroll(eraseAttr);
+
+      assert.strictEqual(buffer.ybase, ybaseBefore);
+      assert.strictEqual(buffer.ydisp, 1);
+    });
+
+    it('should not advance ydisp with ybase while the user has scrolled up and the buffer is not full', () => {
+      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+
+      bufferService.isUserScrolling = true;
+      buffer.ydisp = 0;
+      const ybaseBefore = buffer.ybase;
+
+      bufferService.scroll(eraseAttr);
+
+      assert.strictEqual(buffer.ybase, ybaseBefore + 1);
+      assert.strictEqual(buffer.ydisp, 0);
+    });
+
+    it('should follow ybase with ydisp when the user is not scrolling', () => {
+      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+
+      while (!buffer.lines.isFull) {
+        bufferService.scroll(eraseAttr);
+      }
+
+      bufferService.isUserScrolling = false;
+      bufferService.scroll(eraseAttr);
+
+      assert.strictEqual(buffer.ydisp, buffer.ybase);
+    });
+
+    it('should scroll within DECSTBM margins without affecting lines outside the region', () => {
+      const optionsService = new OptionsService({ rows: 5, cols: 10, scrollback: 10 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+
+      const markRow = (row: number, ch: string) => {
+        buffer.lines.get(buffer.ybase + row)!.setCellFromCodepoint(0, ch.charCodeAt(0), 1, eraseAttr);
+      };
+      markRow(0, 'A');
+      markRow(1, 'B');
+      markRow(2, 'C');
+      markRow(3, 'D');
+      markRow(4, 'E');
+      buffer.scrollTop = 1;
+      buffer.scrollBottom = 3;
+
+      bufferService.scroll(eraseAttr);
+
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 0)!.translateToString().trim(), 'A');
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.translateToString().trim(), 'C');
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 2)!.translateToString().trim(), 'D');
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 3)!.translateToString(true).trim(), '');
+      assert.strictEqual(buffer.lines.get(buffer.ybase + 4)!.translateToString().trim(), 'E');
+    });
+  });
+
+  describe('scrollLines', () => {
+    it('should move ydisp and set isUserScrolling when scrolling up', () => {
+      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+      buffer.ybase = 5;
+      buffer.ydisp = 5;
+
+      let scrollEvent: number | undefined;
+      bufferService.onScroll(e => { scrollEvent = e; });
+
+      bufferService.scrollLines(-2);
+
+      assert.strictEqual(buffer.ydisp, 3);
+      assert.strictEqual(bufferService.isUserScrolling, true);
+      assert.strictEqual(scrollEvent, 3);
+    });
+
+    it('should not scroll above the top of the buffer', () => {
+      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+      buffer.ybase = 5;
+      buffer.ydisp = 0;
+
+      bufferService.scrollLines(-1);
+
+      assert.strictEqual(buffer.ydisp, 0);
+      assert.strictEqual(bufferService.isUserScrolling, false);
+    });
+
+    it('should clear isUserScrolling when scrolling to the bottom', () => {
+      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
+      const bufferService = new BufferService(optionsService, new MockLogService());
+      const buffer = bufferService.buffer;
+      buffer.ybase = 5;
+      buffer.ydisp = 2;
+      bufferService.isUserScrolling = true;
+
+      bufferService.scrollLines(10);
+
+      assert.strictEqual(buffer.ydisp, 5);
+      assert.strictEqual(bufferService.isUserScrolling, false);
+    });
+  });
+});

src/common/services/CharsetService.test.ts

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { CHARSETS } from '../data/Charsets';
+import { CharsetService } from './CharsetService';
+
+describe('CharsetService', () => {
+  let service: CharsetService;
+
+  beforeEach(() => {
+    service = new CharsetService();
+  });
+
+  it('should not update active charset when designating an inactive glevel', () => {
+    service.setgCharset(1, CHARSETS['0']);
+    assert.strictEqual(service.glevel, 0);
+    assert.ok(service.charset === undefined);
+  });
+
+  it('should expose the designated charset after setgLevel', () => {
+    service.setgCharset(1, CHARSETS['0']);
+    service.setgLevel(1);
+    assert.strictEqual(service.charset, CHARSETS['0']);
+  });
+
+  it('should update active charset when designating the current glevel', () => {
+    service.setgLevel(1);
+    service.setgCharset(1, CHARSETS['0']);
+    assert.strictEqual(service.charset, CHARSETS['0']);
+  });
+
+  it('should reset glevel, charsets, and active charset', () => {
+    service.setgCharset(1, CHARSETS['0']);
+    service.setgLevel(1);
+    service.reset();
+    assert.strictEqual(service.glevel, 0);
+    assert.deepEqual(service.charsets, []);
+    assert.ok(service.charset === undefined);
+  });
+});

src/common/services/MouseStateService.ts

@@ -126,7 +126,7 @@ const DEFAULT_ENCODINGS: { [key: string]: CoreMouseEncoding } = {
    */
   DEFAULT: (e: ICoreMouseEvent) => {
     const params = [eventCode(e, false) + 32, e.col + 32, e.row + 32];
-    // suppress mouse report if we exceed addressable range
+    // supress mouse report if we exceed addressible range
     // Note this is handled differently by emulators
     // - xterm:         sends 0;0 coords instead
     // - vte, konsole:  no report

src/common/services/Services.ts

@@ -324,7 +324,7 @@ export interface IOscLinkService {
  * bit 0: shouldJoin - should combine with preceding character.
  * bit 1..2: wcwidth - see UnicodeCharWidth.
  * bit 3..31: class of character (currently only 4 bits are used).
- *   This is used to determine grapheme clustering - i.e. which codepoints
+ *   This is used to determined grapheme clustering - i.e. which codepoints
  *   are to be combined into a single compound character.
  *
  * Use the UnicodeService static function createPropertyValue to create a

src/headless/Terminal.ts

@@ -99,10 +99,6 @@ export class Terminal extends CoreTerminal {
    * Clear the entire buffer, making the prompt line the new first line.
    */
   public clear(): void {
-    if (this.buffer.ybase === 0 && this.buffer.y === 0) {
-      // Don't clear if it's already clear
-      return;
-    }
     this.buffer.clearAllMarkers();
     this.buffer.lines.set(0, this.buffer.lines.get(this.buffer.ybase + this.buffer.y)!);
     this.buffer.lines.length = 1;

test/benchmark/BufferLine.benchmark.ts

@@ -0,0 +1,113 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
+import { BufferLine, DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
+import { BufferLineStringCache } from 'common/buffer/BufferLineStringCache';
+import { CellData } from 'common/buffer/CellData';
+import { BgFlags, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE, UnderlineStyle } from 'common/buffer/Constants';
+
+const ITERATIONS = 500_000;
+const stringCache = new BufferLineStringCache();
+const nullCell = CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
+const yCell = CellData.fromCharData([0, 'y', 1, 'y'.charCodeAt(0)]);
+
+function fillPlainY(line: BufferLine, cols: number): void {
+  for (let i = 0; i < cols; i++) {
+    line.setCellFromCodepoint(i, 'y'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+  }
+}
+
+function setupScrollRecyclePair(cols: number): { recycled: BufferLine, blank: BufferLine } {
+  const blank = new BufferLine(stringCache, cols, nullCell, false);
+  const recycled = new BufferLine(stringCache, cols, yCell, false);
+  fillPlainY(recycled, cols);
+  return { recycled, blank };
+}
+
+/** Source line with combining chars and extended attrs spread across columns. */
+function buildSparseSourceLine(cols: number): BufferLine {
+  const line = new BufferLine(stringCache, cols, nullCell, false);
+  for (let i = 0; i < cols; i++) {
+    if (i % 10 === 0) {
+      const cell = CellData.fromCharData([0, 'a', 1, 'a'.charCodeAt(0)]);
+      cell.extended.underlineStyle = UnderlineStyle.CURLY;
+      cell.bg |= BgFlags.HAS_EXTENDED;
+      line.setCell(i, cell);
+    } else if (i % 17 === 0) {
+      line.setCell(i, CellData.fromCharData([1, 'e\u0301', 1, '\u0301'.charCodeAt(0)]));
+    } else {
+      line.setCellFromCodepoint(i, 'y'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+    }
+  }
+  return line;
+}
+
+function setupCopyFromSparsePair(cols: number): { dest: BufferLine, src: BufferLine } {
+  const src = buildSparseSourceLine(cols);
+  const dest = new BufferLine(stringCache, cols, yCell, false);
+  fillPlainY(dest, cols);
+  return { dest, src };
+}
+
+perfContext('BufferLine.copyFrom (scroll recycle)', () => {
+  perfContext('cols=80', () => {
+    let recycled: BufferLine;
+    let blank: BufferLine;
+    before(() => {
+      ({ recycled, blank } = setupScrollRecyclePair(80));
+    });
+    new RuntimeCase('', () => {
+      for (let i = 0; i < ITERATIONS; i++) {
+        recycled.copyFrom(blank);
+      }
+      return { payloadSize: ITERATIONS };
+    }, { fork: false }).showAverageRuntime();
+  });
+
+  perfContext('cols=279', () => {
+    let recycled: BufferLine;
+    let blank: BufferLine;
+    before(() => {
+      ({ recycled, blank } = setupScrollRecyclePair(279));
+    });
+    new RuntimeCase('', () => {
+      for (let i = 0; i < ITERATIONS; i++) {
+        recycled.copyFrom(blank);
+      }
+      return { payloadSize: ITERATIONS };
+    }, { fork: false }).showAverageRuntime();
+  });
+});
+
+perfContext('BufferLine.copyFrom (sparse source: combined + extended attrs)', () => {
+  perfContext('cols=80', () => {
+    let dest: BufferLine;
+    let src: BufferLine;
+    before(() => {
+      ({ dest, src } = setupCopyFromSparsePair(80));
+    });
+    new RuntimeCase('', () => {
+      for (let i = 0; i < ITERATIONS; i++) {
+        dest.copyFrom(src);
+      }
+      return { payloadSize: ITERATIONS };
+    }, { fork: false }).showAverageRuntime();
+  });
+
+  perfContext('cols=279', () => {
+    let dest: BufferLine;
+    let src: BufferLine;
+    before(() => {
+      ({ dest, src } = setupCopyFromSparsePair(279));
+    });
+    new RuntimeCase('', () => {
+      for (let i = 0; i < ITERATIONS; i++) {
+        dest.copyFrom(src);
+      }
+      return { payloadSize: ITERATIONS };
+    }, { fork: false }).showAverageRuntime();
+  });
+});

test/benchmark/DecorationService.benchmark.ts

@@ -4,8 +4,8 @@
  */
 
 import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
-import { DecorationService } from '../../src/common/services/DecorationService';
+import { DecorationService } from 'common/services/DecorationService';
-import { MockLogService, MockBufferService, MockOptionsService } from '../../src/common/TestUtils.test';
+import { MockLogService, MockBufferService, MockOptionsService } from 'common/TestUtils.test';
 const enum Constants {
   COLS = 80,
   ROWS = 30,

test/benchmark/EscapeSequenceParser.benchmark.ts

@@ -4,12 +4,12 @@
  */
 import { perfContext, before, beforeEach, ThroughputRuntimeCase } from 'xterm-benchmark';
 
-import { EscapeSequenceParser } from '../../src/common/parser/EscapeSequenceParser';
+import { EscapeSequenceParser } from 'common/parser/EscapeSequenceParser';
-import { C0, C1 } from '../../src/common/data/EscapeSequences';
+import { C0, C1 } from 'common/data/EscapeSequences';
-import { IDcsHandler, IOscHandler, IApcHandler, IParams } from '../../src/common/parser/Types';
+import { IDcsHandler, IOscHandler, IApcHandler, IParams } from 'common/parser/Types';
-import { OscHandler } from '../../src/common/parser/OscParser';
+import { OscHandler } from 'common/parser/OscParser';
-import { DcsHandler } from '../../src/common/parser/DcsParser';
+import { DcsHandler } from 'common/parser/DcsParser';
-import { ApcHandler } from '../../src/common/parser/ApcParser';
+import { ApcHandler } from 'common/parser/ApcParser';
 
 const SIZE = 5000000;
 

test/benchmark/Event.benchmark.ts

@@ -4,7 +4,7 @@
  */
 
 import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
-import { Emitter } from '../../src/common/Event';
+import { Emitter } from 'common/Event';
 
 const ITERATIONS = 1_000_000;
 

test/benchmark/Terminal.benchmark.ts

@@ -6,8 +6,8 @@
 import { perfContext, before, ThroughputRuntimeCase } from 'xterm-benchmark';
 
 import { spawn } from 'node-pty';
-import { Utf8ToUtf32, stringFromCodePoint } from '../../src/common/input/TextDecoder';
+import { Utf8ToUtf32, stringFromCodePoint } from 'common/input/TextDecoder';
-import { CoreBrowserTerminal } from '../../src/browser/CoreBrowserTerminal';
+import { CoreBrowserTerminal } from 'browser/CoreBrowserTerminal';
 
 perfContext('Terminal: ls -lR /usr/lib', () => {
   let content = '';

test/benchmark/tsconfig.json

@@ -11,7 +11,11 @@
     "moduleResolution": "nodenext",
     "strict": false,
     "target": "es2021",
-    "module": "nodenext"
+    "module": "nodenext",
+    "paths": {
+      "common/*": ["../../src/common/*"],
+      "browser/*": ["../../src/browser/*"]
+    }
   },
   "include": [
     "./**/*",