Fix #50143

src/vs/workbench/api/node/extHostTreeViews.ts

@@ -362,7 +362,7 @@ class ExtHostTreeView<T> extends Disposable {
 		return item;
 	}
 
-	private createHandle(element: T, { id, label, resourceUri }: vscode.TreeItem, parent: TreeNode, first?: boolean): TreeItemHandle {
+	private createHandle(element: T, { id, label, resourceUri }: vscode.TreeItem, parent: TreeNode, returnFirst?: boolean): TreeItemHandle {
 		if (id) {
 			return `${ExtHostTreeView.ID_HANDLE_PREFIX}/${id}`;
 		}
@@ -373,14 +373,20 @@ class ExtHostTreeView<T> extends Disposable {
 		const existingHandle = this.nodes.has(element) ? this.nodes.get(element).item.handle : void 0;
 		const childrenNodes = (this.getChildrenNodes(parent) || []);
 
-		for (let counter = 0; counter <= childrenNodes.length; counter++) {
-			const handle = `${prefix}/${counter}:${elementId}`;
-			if (first || !this.elements.has(handle) || existingHandle === handle) {
-				return handle;
+		let handle: TreeItemHandle;
+		let counter = 0;
+		do {
+			handle = `${prefix}/${counter}:${elementId}`;
+			if (returnFirst || !this.elements.has(handle) || existingHandle === handle) {
+				// Return first if asked for or
+				// Return if handle does not exist or
+				// Return if handle is being reused
+				break;
 			}
-		}
+			counter++;
+		} while (counter <= childrenNodes.length);
 
-		throw new Error('This should not be reached');
+		return handle;
 	}
 
 	private getLightIconPath(extensionTreeItem: vscode.TreeItem): string {
@@ -457,7 +463,7 @@ class ExtHostTreeView<T> extends Disposable {
 					}
 				}
 			}
-			node.children = [];
+			node.children = void 0;
 		} else {
 			this.clearAll();
 		}