only listen after getting data once, #40210

src/vs/workbench/services/decorations/browser/decorationsService.ts

@@ -230,30 +230,19 @@ class FileDecorationChangeEvent implements IResourceDecorationChangeEvent {
 class DecorationProviderWrapper {
 
 	readonly data = TernarySearchTree.forPaths<Thenable<void> | IDecorationData>();
-	private readonly _dispoable: IDisposable;
+
+	private _listener: IDisposable;
 
 	constructor(
 		private readonly _provider: IDecorationsProvider,
 		private readonly _uriEmitter: Emitter<URI | URI[]>,
 		private readonly _flushEmitter: Emitter<IResourceDecorationChangeEvent>
 	) {
-		this._dispoable = this._provider.onDidChange(uris => {
-			if (!uris) {
-				// flush event -> drop all data, can affect everything
-				this.data.clear();
-				this._flushEmitter.fire({ affectsResource() { return true; } });
-
-			} else {
-				// selective changes -> drop for resource, fetch again, send event
-				for (const uri of uris) {
-					this._fetchData(uri);
-				}
-			}
-		});
+		//
 	}
 
 	dispose(): void {
-		this._dispoable.dispose();
+		this._listener.dispose();
 		this.data.clear();
 	}
 
@@ -294,7 +283,11 @@ class DecorationProviderWrapper {
 	}
 
 	private _fetchData(uri: URI): IDecorationData {
+		// listen to provider changes only after
+		// we have asked it for data...
+		this._ensureIsListening();
 
+		// retrieve data, do the dance
 		const dataOrThenable = this._provider.provideDecorations(uri);
 		if (!isThenable(dataOrThenable)) {
 			// sync -> we have a result now
@@ -320,6 +313,24 @@ class DecorationProviderWrapper {
 		}
 		return deco;
 	}
+
+	private _ensureIsListening(): void {
+		if (!this._listener) {
+			this._listener = this._provider.onDidChange(uris => {
+				if (!uris) {
+					// flush event -> drop all data, can affect everything
+					this.data.clear();
+					this._flushEmitter.fire({ affectsResource() { return true; } });
+
+				} else {
+					// selective changes -> drop for resource, fetch again, send event
+					for (const uri of uris) {
+						this._fetchData(uri);
+					}
+				}
+			});
+		}
+	}
 }
 
 export class FileDecorationsService implements IDecorationsService {