Merge pull request #15313 from atom/as-fix-extra-schedule-update

Ensure extra document updates are not scheduled during `updateSync`

spec/text-editor-component-spec.js

@@ -3610,6 +3610,23 @@ describe('TextEditorComponent', () => {
       element.style.display = 'none'
       await component.getNextUpdatePromise()
     })
+
+    it('does not throw an exception when the editor is soft-wrapped and changing the font size changes also the longest screen line', async () => {
+      const {component, element, editor} = buildComponent({rowsPerTile: 3, autoHeight: false})
+      editor.setText(
+        'Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do\n' +
+        'eiusmod tempor incididunt ut labore et dolore magna' +
+        'aliqua. Ut enim ad minim veniam, quis nostrud exercitation'
+      )
+      editor.setSoftWrapped(true)
+      await setEditorHeightInLines(component, 2)
+      await setEditorWidthInCharacters(component, 56)
+      await setScrollTop(component, 3 * component.getLineHeight())
+
+      element.style.fontSize = '20px'
+      TextEditor.didUpdateStyles()
+      await component.getNextUpdatePromise()
+    })
   })
 
   describe('synchronous updates', () => {

src/text-editor-component.js

@@ -213,15 +213,17 @@ class TextEditorComponent {
   }
 
   updateSync (useScheduler = false) {
-    this.updateScheduled = false
-
     // Don't proceed if we know we are not visible
-    if (!this.visible) return
+    if (!this.visible) {
+      this.updateScheduled = false
+      return
+    }
 
     // Don't proceed if we have to pay for a measurement anyway and detect
     // that we are no longer visible.
     if ((this.remeasureCharacterDimensions || this.remeasureAllBlockDecorations) && !this.isVisible()) {
       if (this.resolveNextUpdatePromise) this.resolveNextUpdatePromise()
+      this.updateScheduled = false
       return
     }
 
@@ -230,6 +232,7 @@ class TextEditorComponent {
     if (useScheduler && onlyBlinkingCursors) {
       this.refs.cursorsAndInput.updateCursorBlinkSync(this.cursorsBlinkedOff)
       if (this.resolveNextUpdatePromise) this.resolveNextUpdatePromise()
+      this.updateScheduled = false
       return
     }
 
@@ -266,6 +269,8 @@ class TextEditorComponent {
       this.measureContentDuringUpdateSync()
       this.updateSyncAfterMeasuringContent()
     }
+
+    this.updateScheduled = false
   }
 
   measureBlockDecorations () {