workaround: TypeError: Cannot read property '_acceptIsDirty' of undefined #952

src/vs/workbench/api/common/pluginHostDocuments.ts

@@ -139,19 +139,25 @@ export class PluginHostModelService {
 
 	public _acceptModelSaved(url: URI): void {
 		let document = this._documents[url.toString()];
+		if (document) {
 			document._acceptIsDirty(false);
 			this._onDidSaveDocumentEventEmitter.fire(document);
 		}
+	}
 
 	public _acceptModelDirty(url: URI): void {
 		let document = this._documents[url.toString()];
+		if (document) {
 			document._acceptIsDirty(true);
 		}
+	}
 
 	public _acceptModelReverted(url: URI): void {
 		let document = this._documents[url.toString()];
+		if (document) {
 			document._acceptIsDirty(false);
 		}
+	}
 
 	public _acceptModelRemoved(url: URI): void {
 		let key = url.toString();