Fix issue with resizing terminal.

Need to ensure the active buffer is always being used.
Fixes https://github.com/xtermjs/xterm.js/issues/824 .

src/Buffer.ts

@@ -121,11 +121,6 @@ export class Buffer implements IBuffer {
       if (this._terminal.cols < newCols) {
         const ch: CharData = [this._terminal.defAttr, ' ', 1, 32]; // does xterm use the default attr?
         for (let i = 0; i < this._lines.length; i++) {
-          // TODO: This should be removed, with tests setup for the case that was
-          // causing the underlying bug, see https://github.com/sourcelair/xterm.js/issues/824
-          if (this._lines.get(i) === undefined) {
-            this._lines.set(i, this._terminal.blankLine(undefined, undefined, newCols));
-          }
           while (this._lines.get(i).length < newCols) {
             this._lines.get(i).push(ch);
           }

src/InputHandler.ts

@@ -928,7 +928,6 @@ export class InputHandler implements IInputHandler {
         case 47: // alt screen buffer
         case 1047: // alt screen buffer
           this._terminal.buffers.activateAltBuffer();
-          this._terminal.selectionManager.setBuffer(this._terminal.buffer);
           this._terminal.viewport.syncScrollArea();
           this._terminal.showCursor();
           break;
@@ -1100,7 +1099,6 @@ export class InputHandler implements IInputHandler {
           // if (params[0] === 1049) {
           //   this.restoreCursor(params);
           // }
-          this._terminal.selectionManager.setBuffer(this._terminal.buffer);
           this._terminal.refresh(0, this._terminal.rows - 1);
           this._terminal.viewport.syncScrollArea();
           this._terminal.showCursor();

src/Interfaces.ts

@@ -198,7 +198,6 @@ export interface ISelectionManager {
 
   disable(): void;
   enable(): void;
-  setBuffer(buffer: IBuffer): void;
   setSelection(row: number, col: number, length: number): void;
 }
 

src/SelectionManager.test.ts

@@ -21,10 +21,9 @@ class TestMockTerminal extends MockTerminal {
 class TestSelectionManager extends SelectionManager {
   constructor(
     terminal: ITerminal,
-    buffer: IBuffer,
     charMeasure: CharMeasure
   ) {
-    super(terminal, buffer, charMeasure);
+    super(terminal, charMeasure);
   }
 
   public get model(): SelectionModel { return this._model; }
@@ -59,7 +58,7 @@ describe('SelectionManager', () => {
     terminal.buffers = new BufferSet(terminal);
     terminal.buffer = terminal.buffers.active;
     buffer = terminal.buffer;
-    selectionManager = new TestSelectionManager(terminal, buffer, null);
+    selectionManager = new TestSelectionManager(terminal, null);
   });
 
   function stringToRow(text: string): LineData {

src/SelectionManager.ts

@@ -98,7 +98,6 @@ export class SelectionManager extends EventEmitter implements ISelectionManager
 
   constructor(
     private _terminal: ITerminal,
-    private _buffer: IBuffer,
     private _charMeasure: CharMeasure
   ) {
     super();
@@ -109,6 +108,10 @@ export class SelectionManager extends EventEmitter implements ISelectionManager
     this._activeSelectionMode = SelectionMode.NORMAL;
   }
 
+  private get _buffer(): IBuffer {
+      return this._terminal.buffers.active;
+  }
+
   /**
    * Initializes listener variables.
    */
@@ -139,16 +142,6 @@ export class SelectionManager extends EventEmitter implements ISelectionManager
     this._enabled = true;
   }
 
-  /**
-   * Sets the active buffer, this should be called when the alt buffer is
-   * switched in or out.
-   * @param buffer The active buffer.
-   */
-  public setBuffer(buffer: IBuffer): void {
-    this._buffer = buffer;
-    this.clearSelection();
-  }
-
   public get selectionStart(): [number, number] { return this._model.finalSelectionStart; }
   public get selectionEnd(): [number, number] { return this._model.finalSelectionEnd; }
 

src/Terminal.ts

@@ -192,7 +192,6 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
   public selectionManager: SelectionManager;
   public linkifier: ILinkifier;
   public buffers: BufferSet;
-  public buffer: Buffer;
   public viewport: IViewport;
   private compositionHelper: ICompositionHelper;
   public charMeasure: CharMeasure;
@@ -293,15 +292,13 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
 
     // Create the terminal's buffers and set the current buffer
     this.buffers = new BufferSet(this);
-    this.buffer = this.buffers.active;  // Convenience shortcut;
-    this.buffers.on('activate', (buffer: Buffer) => {
-      this.buffer = buffer;
-    });
+  }
 
-    // Ensure the selection manager has the correct buffer
-    if (this.selectionManager) {
-      this.selectionManager.setBuffer(this.buffer);
-    }
+  /**
+   * Convenience property to active buffer.
+   */
+  public get buffer(): Buffer {
+      return this.buffers.active;
   }
 
   /**
@@ -640,7 +637,7 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
     this.charMeasure.on('charsizechanged', () => this.renderer.onResize(this.cols, this.rows, true));
     this.renderer.on('resize', (dimensions) => this.viewport.syncScrollArea());
 
-    this.selectionManager = new SelectionManager(this, this.buffer, this.charMeasure);
+    this.selectionManager = new SelectionManager(this, this.charMeasure);
     this.element.addEventListener('mousedown', (e: MouseEvent) => this.selectionManager.onMouseDown(e));
     this.selectionManager.on('refresh', data => this.renderer.onSelectionChanged(data.start, data.end));
     this.selectionManager.on('newselection', text => {
@@ -2079,11 +2076,9 @@ export class Terminal extends EventEmitter implements ITerminal, IInputHandlingT
     this.options.cols = this.cols;
     const customKeyEventHandler = this.customKeyEventHandler;
     const inputHandler = this.inputHandler;
-    const buffers = this.buffers;
     this.setup();
     this.customKeyEventHandler = customKeyEventHandler;
     this.inputHandler = inputHandler;
-    this.buffers = buffers;
     this.refresh(0, this.rows - 1);
     this.viewport.syncScrollArea();
   }