src/vs/workbench/services/workspaces/electron-sandbox/workspaceEditingService.ts/NativeWorkspaceEditingService/isValidTargetWorkspacePath
class NativeWorkspaceEditingService:	override async isValidTargetWorkspacePath(workspaceUri: URI): Promise<boolean> {
		const windows = await this.nativeHostService.getWindows();

		// Prevent overwriting a workspace that is currently opened in another window
		if (windows.some(window => isWorkspaceIdentifier(window.workspace) && this.uriIdentityService.extUri.isEqual(window.workspace.configPath, workspaceUri))) {
			await this.dialogService.show(
				Severity.Info,
				localize('workspaceOpenedMessage', "Unable to save workspace '{0}'", basename(workspaceUri)),
				undefined,
				{
					detail: localize('workspaceOpenedDetail', "The workspace is already opened in another window. Please close that window first and then try again.")
				}
			);

			return false;
		}

		return true; // OK
	}