Fix issue with kernel preselection being overridden by view state (#154968)

* Fix view state overriding selected kernel

* Add test to verify correct kernel is used

extensions/vscode-api-tests/src/singlefolder-tests/interactiveWindow.test.ts

@@ -17,7 +17,7 @@ async function createInteractiveWindow(kernel: Kernel) {
 		// Keep focus on the owning file if there is one
 		{ viewColumn: vscode.ViewColumn.Beside, preserveFocus: false },
 		undefined,
-		kernel.controller.id,
+		`vscode.vscode-api-tests/${kernel.controller.id}`,
 		undefined
 	)) as unknown as INativeInteractiveWindow;
 
@@ -45,11 +45,13 @@ async function addCellAndRun(code: string, notebook: vscode.NotebookDocument, i:
 
 	const testDisposables: vscode.Disposable[] = [];
 	let defaultKernel: Kernel;
+	let secondKernel: Kernel;
 
 	setup(async function () {
-		// there should be ONE default kernel in this suite
 		defaultKernel = new Kernel('mainKernel', 'Notebook Default Kernel', 'interactive');
+		secondKernel = new Kernel('secondKernel', 'Notebook Secondary Kernel', 'interactive');
 		testDisposables.push(defaultKernel.controller);
+		testDisposables.push(secondKernel.controller);
 		await saveAllFilesAndCloseAll();
 	});
 
@@ -85,4 +87,22 @@ async function addCellAndRun(code: string, notebook: vscode.NotebookDocument, i:
 		assert.strictEqual(notebookEditor.visibleRanges[notebookEditor.visibleRanges.length - 1].end, notebookEditor.notebook.cellCount, `Last cell is not visible`);
 
 	});
+
+	test('Interactive window has the correct kernel', async () => {
+		assert.ok(vscode.workspace.workspaceFolders);
+		const notebookEditor = await createInteractiveWindow(defaultKernel);
+		assert.ok(notebookEditor);
+
+		await vscode.commands.executeCommand('workbench.action.closeActiveEditor');
+
+		// Create a new interactive window with a different kernel
+		const notebookEditor2 = await createInteractiveWindow(secondKernel);
+		assert.ok(notebookEditor2);
+
+		// Verify the kernel is the secondary one
+		await addCellAndRun(`print`, notebookEditor2.notebook, 0);
+
+		assert.strictEqual(secondKernel.associatedNotebooks.has(notebookEditor2.notebook.uri.toString()), true, `Secondary kernel was not set as the kernel for the interactive window`);
+
+	});
 });

src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts

@@ -1693,8 +1693,11 @@ export class NotebookEditorWidget extends Disposable implements INotebookEditorD
 
 	private _restoreSelectedKernel(viewState: INotebookEditorViewState | undefined): void {
 		if (viewState?.selectedKernelId && this.textModel) {
-			const kernel = this.notebookKernelService.getMatchingKernel(this.textModel).all.find(k => k.id === viewState.selectedKernelId);
+			const matching = this.notebookKernelService.getMatchingKernel(this.textModel);
-			if (kernel) {
+			const kernel = matching.all.find(k => k.id === viewState.selectedKernelId);
+			// Selected kernel may have already been picked prior to the view state loading
+			// If so, don't overwrite it with the saved kernel.
+			if (kernel && !matching.selected) {
 				this.notebookKernelService.selectKernelForNotebook(kernel, this.textModel);
 			}
 		}