fix #4582

src/browser/Terminal.ts

@@ -747,8 +747,10 @@ export class Terminal extends CoreTerminal implements ITerminal {
 
       if (!(events & CoreMouseEventType.UP)) {
         this._document!.removeEventListener('mouseup', requestedEvents.mouseup!);
+        el.removeEventListener('mouseup', requestedEvents.mouseup!);
         requestedEvents.mouseup = null;
       } else if (!requestedEvents.mouseup) {
+        el.addEventListener('mouseup', eventListeners.mouseup);
         requestedEvents.mouseup = eventListeners.mouseup;
       }
 

src/browser/services/MouseService.ts

@@ -31,17 +31,11 @@ export class MouseService implements IMouseService {
 
   public getMouseReportCoords(event: MouseEvent, element: HTMLElement): { col: number, row: number, x: number, y: number } | undefined {
     const coords = getCoordsRelativeToElement(window, event, element);
-
+    if (!this._charSizeService.hasValidSize) {
-    // due to rounding issues in zoom states pixel values might be negative or overflow actual canvas
-    // ignore those events effectively narrowing mouse area a tiny bit at the edges
-    if (!this._charSizeService.hasValidSize
-      || coords[0] < 0
-      || coords[1] < 0
-      || coords[0] >= this._renderService.dimensions.css.canvas.width
-      || coords[1] >= this._renderService.dimensions.css.canvas.height) {
       return undefined;
     }
-
+    coords[0] = Math.min(Math.max(coords[0], 0), this._renderService.dimensions.css.canvas.width - 1);
+    coords[1] = Math.min(Math.max(coords[1], 0), this._renderService.dimensions.css.canvas.height - 1);
     return {
       col: Math.floor(coords[0] / this._renderService.dimensions.css.cell.width),
       row: Math.floor(coords[1] / this._renderService.dimensions.css.cell.height),

src/common/services/CoreMouseService.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 import { IBufferService, ICoreService, ICoreMouseService } from 'common/services/Services';
-import { EventEmitter, IEvent } from 'common/EventEmitter';
+import { EventEmitter } from 'common/EventEmitter';
 import { ICoreMouseProtocol, ICoreMouseEvent, CoreMouseEncoding, CoreMouseEventType, CoreMouseButton, CoreMouseAction } from 'common/Types';
 import { Disposable } from 'common/Lifecycle';