Merge branch 'master' into buffer_optimizations

src/common/TaskQueue.ts

@@ -71,6 +71,8 @@ abstract class TaskQueue implements ITaskQueue {
     this._idleCallback = undefined;
     let taskDuration = 0;
     let longestTask = 0;
+    let lastDeadlineRemaining = deadline.timeRemaining();
+    let deadlineRemaining = 0;
     while (this._i < this._tasks.length) {
       taskDuration = Date.now();
       if (!this._tasks[this._i]()) {
@@ -83,10 +85,17 @@ abstract class TaskQueue implements ITaskQueue {
       longestTask = Math.max(taskDuration, longestTask);
       // Guess the following task will take a similar time to the longest task in this batch, allow
       // additional room to try avoid exceeding the deadline
-      if (longestTask * 1.5 > deadline.timeRemaining()) {
+      deadlineRemaining = deadline.timeRemaining();
+      if (longestTask * 1.5 > deadlineRemaining) {
+        // Warn when the time exceeding the deadline is over 20ms, if this happens in practice the
+        // task should be split into sub-tasks to ensure the UI remains responsive.
+        if (lastDeadlineRemaining - taskDuration < -20) {
+          console.warn(`task queue exceeded allotted deadline by ${Math.abs(Math.round(lastDeadlineRemaining - taskDuration))}ms`);
+        }
         this._start();
         return;
       }
+      lastDeadlineRemaining = deadlineRemaining;
     }
     this.clear();
   }

src/common/input/Keyboard.test.ts

@@ -125,6 +125,12 @@ describe('Keyboard', () => {
       it('should return \\x1ba for alt+a', () => {
         assert.equal(testEvaluateKeyboardEvent({ altKey: true, keyCode: 65 }, { isMac: false }).key, '\x1ba');
       });
+      it('should return \\x1b\\x20 for alt+space', () => {
+        assert.equal(testEvaluateKeyboardEvent({ altKey: true, keyCode: 32 }, { isMac: false }).key, '\x1b\x20');
+      });
+      it('should return \\x1b\\x00 for ctrl+alt+space', () => {
+        assert.equal(testEvaluateKeyboardEvent({ altKey: true, ctrlKey: true, keyCode: 32 }, { isMac: false }).key, '\x1b\x00');
+      });
     });
 
     describe('On macOS platforms', () => {

src/common/input/Keyboard.ts

@@ -360,6 +360,8 @@ export function evaluateKeyboardEvent(
             keyString = keyString.toUpperCase();
           }
           result.key = C0.ESC + keyString;
+        } else if (ev.keyCode === 32) {
+          result.key = C0.ESC + (ev.ctrlKey ? C0.NUL : ' ');
         } else if (ev.key === 'Dead' && ev.code.startsWith('Key')) {
           // Reference: https://github.com/xtermjs/xterm.js/issues/3725
           // Alt will produce a "dead key" (initate composition) with some