Fix issue where stale model change events were interpreted

alexdima · alexdima · commit e573b301ef89 · 2017-04-28T00:49:03.000+02:00
diff --git a/src/vs/editor/common/viewModel/splitLinesCollection.ts b/src/vs/editor/common/viewModel/splitLinesCollection.ts
@@ -562,7 +562,13 @@ export class SplitLinesCollection {
 		eventsCollector.emit(new viewEvents.ViewFlushedEvent());
 	}
 
-	public onModelLinesDeleted(eventsCollector: ViewEventsCollector, fromLineNumber: number, toLineNumber: number): void {
+	public onModelLinesDeleted(eventsCollector: ViewEventsCollector, versionId: number, fromLineNumber: number, toLineNumber: number): void {
+		if (versionId <= this._validModelVersionId) {
+			// Here we check for versionId in case the lines were reconstructed in the meantime.
+			// We don't want to apply stale change events on top of a newer read model state.
+			return;
+		}
+
 		let outputFromLineNumber = (fromLineNumber === 1 ? 1 : this.prefixSumComputer.getAccumulatedValue(fromLineNumber - 2) + 1);
 		let outputToLineNumber = this.prefixSumComputer.getAccumulatedValue(toLineNumber - 1);
 
@@ -572,7 +578,13 @@ export class SplitLinesCollection {
 		eventsCollector.emit(new viewEvents.ViewLinesDeletedEvent(outputFromLineNumber, outputToLineNumber));
 	}
 
-	public onModelLinesInserted(eventsCollector: ViewEventsCollector, fromLineNumber: number, toLineNumber: number, text: string[]): void {
+	public onModelLinesInserted(eventsCollector: ViewEventsCollector, versionId: number, fromLineNumber: number, toLineNumber: number, text: string[]): void {
+		if (versionId <= this._validModelVersionId) {
+			// Here we check for versionId in case the lines were reconstructed in the meantime.
+			// We don't want to apply stale change events on top of a newer read model state.
+			return;
+		}
+
 		let hiddenAreas = this.getHiddenAreas();
 		let isInHiddenArea = false;
 		let testPosition = new Position(fromLineNumber, 1);
@@ -605,7 +617,13 @@ export class SplitLinesCollection {
 		eventsCollector.emit(new viewEvents.ViewLinesInsertedEvent(outputFromLineNumber, outputFromLineNumber + totalOutputLineCount - 1));
 	}
 
-	public onModelLineChanged(eventsCollector: ViewEventsCollector, lineNumber: number, newText: string): boolean {
+	public onModelLineChanged(eventsCollector: ViewEventsCollector, versionId: number, lineNumber: number, newText: string): boolean {
+		if (versionId <= this._validModelVersionId) {
+			// Here we check for versionId in case the lines were reconstructed in the meantime.
+			// We don't want to apply stale change events on top of a newer read model state.
+			return false;
+		}
+
 		let lineIndex = lineNumber - 1;
 
 		let oldOutputLineCount = this.lines[lineIndex].getViewLineCount();
diff --git a/src/vs/editor/common/viewModel/viewModelImpl.ts b/src/vs/editor/common/viewModel/viewModelImpl.ts
@@ -303,9 +303,11 @@ export class ViewModel extends Disposable implements IViewModel {
 
 				case textModelEvents.TextModelEventType.ModelRawContentChanged2: {
 					const e = <textModelEvents.ModelRawContentChangedEvent>data;
+					const changes = e.changes;
+					const versionId = e.versionId;
 
-					for (let j = 0, lenJ = e.changes.length; j < lenJ; j++) {
-						const change = e.changes[j];
+					for (let j = 0, lenJ = changes.length; j < lenJ; j++) {
+						const change = changes[j];
 
 						switch (change.changeType) {
 							case textModelEvents.RawContentChangedType.Flush:
@@ -315,25 +317,21 @@ export class ViewModel extends Disposable implements IViewModel {
 								break;
 
 							case textModelEvents.RawContentChangedType.LinesDeleted:
-								this.lines.onModelLinesDeleted(eventsCollector, change.fromLineNumber, change.toLineNumber);
+								this.lines.onModelLinesDeleted(eventsCollector, versionId, change.fromLineNumber, change.toLineNumber);
 								hadOtherModelChange = true;
 								break;
 
 							case textModelEvents.RawContentChangedType.LinesInserted:
-								this.lines.onModelLinesInserted(eventsCollector, change.fromLineNumber, change.toLineNumber, change.detail.split('\n'));
+								this.lines.onModelLinesInserted(eventsCollector, versionId, change.fromLineNumber, change.toLineNumber, change.detail.split('\n'));
 								hadOtherModelChange = true;
 								break;
 
 							case textModelEvents.RawContentChangedType.LineChanged:
-								hadModelLineChangeThatChangedLineMapping = this.lines.onModelLineChanged(eventsCollector, change.lineNumber, change.detail);
+								hadModelLineChangeThatChangedLineMapping = this.lines.onModelLineChanged(eventsCollector, versionId, change.lineNumber, change.detail);
 								break;
-
-							default:
-								console.info('ViewModel received unknown event: ');
-								console.info(_e);
 						}
 					}
-					this.lines.acceptVersionId(e.versionId);
+					this.lines.acceptVersionId(versionId);
 
 					break;
 				}
