Fix #69689

src/vs/workbench/api/electron-browser/mainThreadOutputService.ts

@@ -86,8 +86,11 @@ export class MainThreadOutputService extends Disposable implements MainThreadOut
 
 	public $close(channelId: string): Promise<void> | undefined {
 		const panel = this._panelService.getActivePanel();
-		if (panel && panel.getId() === OUTPUT_PANEL_ID && channelId === this._outputService.getActiveChannel().id) {
-			this._partService.setPanelHidden(true);
+		if (panel && panel.getId() === OUTPUT_PANEL_ID) {
+			const activeChannel = this._outputService.getActiveChannel();
+			if (activeChannel && channelId === activeChannel.id) {
+				this._partService.setPanelHidden(true);
+			}
 		}
 
 		return undefined;
@@ -101,7 +104,7 @@ export class MainThreadOutputService extends Disposable implements MainThreadOut
 		return undefined;
 	}
 
-	private _getChannel(channelId: string): IOutputChannel {
+	private _getChannel(channelId: string): IOutputChannel | null {
 		return this._outputService.getChannel(channelId);
 	}
 }

src/vs/workbench/contrib/output/browser/logViewer.ts

@@ -17,7 +17,7 @@ import { ResourceEditorInput } from 'vs/workbench/common/editor/resourceEditorIn
 import { URI } from 'vs/base/common/uri';
 import { ITextModelService } from 'vs/editor/common/services/resolverService';
 import { IHashService } from 'vs/workbench/services/hash/common/hashService';
-import { LOG_SCHEME, IOutputChannelDescriptor } from 'vs/workbench/contrib/output/common/output';
+import { LOG_SCHEME, IFileOutputChannelDescriptor } from 'vs/workbench/contrib/output/common/output';
 import { IEditorGroupsService } from 'vs/workbench/services/editor/common/editorGroupsService';
 import { IEditorService } from 'vs/workbench/services/editor/common/editorService';
 import { IWindowService } from 'vs/platform/windows/common/windows';
@@ -26,7 +26,7 @@ export class LogViewerInput extends ResourceEditorInput {
 
 	public static readonly ID = 'workbench.editorinputs.output';
 
-	constructor(private outputChannelDescriptor: IOutputChannelDescriptor,
+	constructor(private outputChannelDescriptor: IFileOutputChannelDescriptor,
 		@ITextModelService textModelResolverService: ITextModelService,
 		@IHashService hashService: IHashService
 	) {

src/vs/workbench/contrib/output/browser/outputActions.ts

@@ -6,7 +6,7 @@
 import * as nls from 'vs/nls';
 import * as aria from 'vs/base/browser/ui/aria/aria';
 import { IAction, Action } from 'vs/base/common/actions';
-import { IOutputService, OUTPUT_PANEL_ID, IOutputChannelRegistry, Extensions as OutputExt, IOutputChannelDescriptor } from 'vs/workbench/contrib/output/common/output';
+import { IOutputService, OUTPUT_PANEL_ID, IOutputChannelRegistry, Extensions as OutputExt, IOutputChannelDescriptor, IFileOutputChannelDescriptor } from 'vs/workbench/contrib/output/common/output';
 import { SelectActionItem } from 'vs/base/browser/ui/actionbar/actionbar';
 import { IPartService } from 'vs/workbench/services/part/common/partService';
 import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
@@ -50,9 +50,11 @@ export class ClearOutputAction extends Action {
 	}
 
 	public run(): Promise<boolean> {
-		this.outputService.getActiveChannel().clear();
-		aria.status(nls.localize('outputCleared', "Output was cleared"));
-
+		const activeChannel = this.outputService.getActiveChannel();
+		if (activeChannel) {
+			activeChannel.clear();
+			aria.status(nls.localize('outputCleared', "Output was cleared"));
+		}
 		return Promise.resolve(true);
 	}
 }
@@ -70,7 +72,12 @@ export class ToggleOrSetOutputScrollLockAction extends Action {
 	constructor(id: string, label: string,
 		@IOutputService private readonly outputService: IOutputService) {
 		super(id, label, 'output-action output-scroll-unlock');
-		this.toDispose.push(this.outputService.onActiveOutputChannel(channel => this.setClass(this.outputService.getActiveChannel().scrollLock)));
+		this.toDispose.push(this.outputService.onActiveOutputChannel(channel => {
+			const activeChannel = this.outputService.getActiveChannel();
+			if (activeChannel) {
+				this.setClass(activeChannel.scrollLock);
+			}
+		}));
 	}
 
 	public run(newLockState?: boolean): Promise<boolean> {
@@ -113,7 +120,7 @@ export class SwitchOutputAction extends Action {
 		this.class = 'output-action switch-to-output';
 	}
 
-	public run(channelId?: string): Promise<any> {
+	public run(channelId: string): Promise<any> {
 		return this.outputService.showChannel(channelId);
 	}
 }
@@ -134,12 +141,12 @@ export class SwitchOutputActionItem extends SelectActionItem {
 		super(null, action, [], 0, contextViewService, { ariaLabel: nls.localize('outputChannels', 'Output Channels.') });
 
 		let outputChannelRegistry = Registry.as<IOutputChannelRegistry>(OutputExt.OutputChannels);
-		this.toDispose.push(outputChannelRegistry.onDidRegisterChannel(() => this.updateOtions(this.outputService.getActiveChannel().id)));
-		this.toDispose.push(outputChannelRegistry.onDidRemoveChannel(() => this.updateOtions(this.outputService.getActiveChannel().id)));
-		this.toDispose.push(this.outputService.onActiveOutputChannel(activeChannelId => this.updateOtions(activeChannelId)));
+		this.toDispose.push(outputChannelRegistry.onDidRegisterChannel(() => this.updateOtions()));
+		this.toDispose.push(outputChannelRegistry.onDidRemoveChannel(() => this.updateOtions()));
+		this.toDispose.push(this.outputService.onActiveOutputChannel(() => this.updateOtions()));
 		this.toDispose.push(attachSelectBoxStyler(this.selectBox, themeService));
 
-		this.updateOtions(this.outputService.getActiveChannel().id);
+		this.updateOtions();
 	}
 
 	protected getActionContext(option: string, index: number): string {
@@ -147,30 +154,34 @@ export class SwitchOutputActionItem extends SelectActionItem {
 		return channel ? channel.id : option;
 	}
 
-	private updateOtions(selectedChannel: string): void {
-		const groups = groupBy(this.outputService.getChannelDescriptors(), (c1: IOutputChannelDescriptor, c2: IOutputChannelDescriptor) => {
-			if (!c1.log && c2.log) {
-				return -1;
-			}
-			if (c1.log && !c2.log) {
-				return 1;
-			}
-			return 0;
-		});
-		this.outputChannels = groups[0] || [];
-		this.logChannels = groups[1] || [];
-		const showSeparator = this.outputChannels.length && this.logChannels.length;
-		const separatorIndex = showSeparator ? this.outputChannels.length : -1;
-		const options: string[] = [...this.outputChannels.map(c => c.label), ...(showSeparator ? [SwitchOutputActionItem.SEPARATOR] : []), ...this.logChannels.map(c => nls.localize('logChannel', "Log ({0})", c.label))];
-		let selected = 0;
-		if (selectedChannel) {
-			selected = this.outputChannels.map(c => c.id).indexOf(selectedChannel);
-			if (selected === -1) {
-				const logChannelIndex = this.logChannels.map(c => c.id).indexOf(selectedChannel);
-				selected = logChannelIndex !== -1 ? separatorIndex + 1 + logChannelIndex : 0;
+	private updateOtions(): void {
+		const activeChannel = this.outputService.getActiveChannel();
+		if (activeChannel) {
+			const selectedChannel = activeChannel.id;
+			const groups = groupBy(this.outputService.getChannelDescriptors(), (c1: IOutputChannelDescriptor, c2: IOutputChannelDescriptor) => {
+				if (!c1.log && c2.log) {
+					return -1;
+				}
+				if (c1.log && !c2.log) {
+					return 1;
+				}
+				return 0;
+			});
+			this.outputChannels = groups[0] || [];
+			this.logChannels = groups[1] || [];
+			const showSeparator = this.outputChannels.length && this.logChannels.length;
+			const separatorIndex = showSeparator ? this.outputChannels.length : -1;
+			const options: string[] = [...this.outputChannels.map(c => c.label), ...(showSeparator ? [SwitchOutputActionItem.SEPARATOR] : []), ...this.logChannels.map(c => nls.localize('logChannel', "Log ({0})", c.label))];
+			let selected = 0;
+			if (selectedChannel) {
+				selected = this.outputChannels.map(c => c.id).indexOf(selectedChannel);
+				if (selected === -1) {
+					const logChannelIndex = this.logChannels.map(c => c.id).indexOf(selectedChannel);
+					selected = logChannelIndex !== -1 ? separatorIndex + 1 + logChannelIndex : 0;
+				}
 			}
+			this.setOptions(options.map((label, index) => <ISelectOptionItem>{ text: label, isDisabled: (index === separatorIndex ? true : undefined) }), Math.max(0, selected));
 		}
-		this.setOptions(options.map((label, index) => <ISelectOptionItem>{ text: label, isDisabled: (index === separatorIndex ? true : undefined) }), Math.max(0, selected));
 	}
 }
 
@@ -192,17 +203,23 @@ export class OpenLogOutputFile extends Action {
 	}
 
 	private update(): void {
-		const outputChannelDescriptor = this.getOutputChannelDescriptor();
-		this.enabled = !!(outputChannelDescriptor && outputChannelDescriptor.file && outputChannelDescriptor.log);
+		this.enabled = !!this.getLogFileOutputChannelDescriptor();
 	}
 
 	public run(): Promise<any> {
-		return this.enabled ? this.editorService.openEditor(this.instantiationService.createInstance(LogViewerInput, this.getOutputChannelDescriptor())).then(() => null) : Promise.resolve(null);
+		const logFileOutputChannelDescriptor = this.getLogFileOutputChannelDescriptor();
+		return logFileOutputChannelDescriptor ? this.editorService.openEditor(this.instantiationService.createInstance(LogViewerInput, logFileOutputChannelDescriptor)).then(() => null) : Promise.resolve(null);
 	}
 
-	private getOutputChannelDescriptor(): IOutputChannelDescriptor {
+	private getLogFileOutputChannelDescriptor(): IFileOutputChannelDescriptor | null {
 		const channel = this.outputService.getActiveChannel();
-		return channel ? this.outputService.getChannelDescriptors().filter(c => c.id === channel.id)[0] : null;
+		if (channel) {
+			const descriptor = this.outputService.getChannelDescriptors().filter(c => c.id === channel.id)[0];
+			if (descriptor && descriptor.file && descriptor.log) {
+				return <IFileOutputChannelDescriptor>descriptor;
+			}
+		}
+		return null;
 	}
 }
 
@@ -219,15 +236,15 @@ export class ShowLogsOutputChannelAction extends Action {
 	}
 
 	run(): Promise<void> {
-		const entries: IQuickPickItem[] = this.outputService.getChannelDescriptors().filter(c => c.file && c.log)
-			.map(({ id, label }) => (<IQuickPickItem>{ id, label }));
+		const entries: { id: string, label: string }[] = this.outputService.getChannelDescriptors().filter(c => c.file && c.log)
+			.map(({ id, label }) => ({ id, label }));
 
 		return this.quickInputService.pick(entries, { placeHolder: nls.localize('selectlog', "Select Log") })
 			.then(entry => {
 				if (entry) {
 					return this.outputService.showChannel(entry.id);
 				}
-				return null;
+				return undefined;
 			});
 	}
 }
@@ -257,9 +274,9 @@ export class OpenOutputLogFileAction extends Action {
 		return this.quickInputService.pick(entries, { placeHolder: nls.localize('selectlogFile', "Select Log file") })
 			.then(entry => {
 				if (entry) {
-					return this.editorService.openEditor(this.instantiationService.createInstance(LogViewerInput, entry.channel)).then(() => null);
+					return this.editorService.openEditor(this.instantiationService.createInstance(LogViewerInput, entry.channel)).then(() => undefined);
 				}
-				return null;
+				return undefined;
 			});
 	}
 }
\ No newline at end of file

src/vs/workbench/contrib/output/browser/outputPanel.ts

@@ -75,7 +75,7 @@ export class OutputPanel extends AbstractTextResourceEditor {
 		return this.actions;
 	}
 
-	public getActionItem(action: Action): IActionItem {
+	public getActionItem(action: Action): IActionItem | null {
 		if (action.id === SwitchOutputAction.ID) {
 			return this.instantiationService.createInstance(SwitchOutputActionItem, action);
 		}
@@ -154,11 +154,14 @@ export class OutputPanel extends AbstractTextResourceEditor {
 				return;
 			}
 
-			const newPositionLine = e.position.lineNumber;
-			const lastLine = codeEditor.getModel().getLineCount();
-			const newLockState = lastLine !== newPositionLine;
-			const lockAction = this.actions.filter((action) => action.id === ToggleOrSetOutputScrollLockAction.ID)[0];
-			lockAction.run(newLockState);
+			const model = codeEditor.getModel();
+			if (model) {
+				const newPositionLine = e.position.lineNumber;
+				const lastLine = model.getLineCount();
+				const newLockState = lastLine !== newPositionLine;
+				const lockAction = this.actions.filter((action) => action.id === ToggleOrSetOutputScrollLockAction.ID)[0];
+				lockAction.run(newLockState);
+			}
 		});
 	}
 

src/vs/workbench/contrib/output/common/output.ts

@@ -68,7 +68,7 @@ export interface IOutputService {
 	 * Given the channel id returns the output channel instance.
 	 * Channel should be first registered via OutputChannelRegistry.
 	 */
-	getChannel(id: string): IOutputChannel;
+	getChannel(id: string): IOutputChannel | null;
 
 	/**
 	 * Returns an array of all known output channels descriptors.
@@ -79,7 +79,7 @@ export interface IOutputService {
 	 * Returns the currently active channel.
 	 * Only one channel can be active at a given moment.
 	 */
-	getActiveChannel(): IOutputChannel;
+	getActiveChannel(): IOutputChannel | null;
 
 	/**
 	 * Show the channel with the passed id.
@@ -137,6 +137,10 @@ export interface IOutputChannelDescriptor {
 	file?: URI;
 }
 
+export interface IFileOutputChannelDescriptor extends IOutputChannelDescriptor {
+	file: URI;
+}
+
 export interface IOutputChannelRegistry {
 
 	readonly onDidRegisterChannel: Event<string>;

src/vs/workbench/contrib/output/electron-browser/output.contribution.ts

@@ -30,7 +30,6 @@ registerSingleton(IOutputService, OutputService);
 ModesRegistry.registerLanguage({
 	id: OUTPUT_MODE_ID,
 	extensions: [],
-	aliases: [null],
 	mimetypes: [OUTPUT_MIME]
 });
 
@@ -38,7 +37,6 @@ ModesRegistry.registerLanguage({
 ModesRegistry.registerLanguage({
 	id: LOG_MODE_ID,
 	extensions: [],
-	aliases: [null],
 	mimetypes: [LOG_MIME]
 });
 
@@ -99,7 +97,10 @@ registerAction({
 		when: CONTEXT_IN_OUTPUT
 	},
 	handler(accessor) {
-		accessor.get(IOutputService).getActiveChannel().clear();
+		const activeChannel = accessor.get(IOutputService).getActiveChannel();
+		if (activeChannel) {
+			activeChannel.clear();
+		}
 	}
 });
 

src/vs/workbench/contrib/output/electron-browser/outputServices.ts

@@ -14,7 +14,7 @@ import { IInstantiationService } from 'vs/platform/instantiation/common/instanti
 import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
 import { Registry } from 'vs/platform/registry/common/platform';
 import { EditorOptions } from 'vs/workbench/common/editor';
-import { IOutputChannelDescriptor, IOutputChannel, IOutputService, Extensions, OUTPUT_PANEL_ID, IOutputChannelRegistry, OUTPUT_SCHEME, OUTPUT_MIME, LOG_SCHEME, LOG_MIME, CONTEXT_ACTIVE_LOG_OUTPUT, MAX_OUTPUT_LENGTH } from 'vs/workbench/contrib/output/common/output';
+import { IOutputChannelDescriptor, IOutputChannel, IOutputService, Extensions, OUTPUT_PANEL_ID, IOutputChannelRegistry, OUTPUT_SCHEME, OUTPUT_MIME, LOG_SCHEME, LOG_MIME, CONTEXT_ACTIVE_LOG_OUTPUT, MAX_OUTPUT_LENGTH, IFileOutputChannelDescriptor } from 'vs/workbench/contrib/output/common/output';
 import { OutputPanel } from 'vs/workbench/contrib/output/browser/outputPanel';
 import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
 import { IModelService } from 'vs/editor/common/services/modelService';
@@ -44,7 +44,7 @@ import { isNumber } from 'vs/base/common/types';
 const OUTPUT_ACTIVE_CHANNEL_KEY = 'output.activechannel';
 
 let watchingOutputDir = false;
-let callbacks: ((eventType: string, fileName: string) => void)[] = [];
+let callbacks: ((eventType: string, fileName?: string) => void)[] = [];
 function watchOutputDirectory(outputDir: string, logService: ILogService, onChange: (eventType: string, fileName: string) => void): IDisposable {
 	callbacks.push(onChange);
 	if (!watchingOutputDir) {
@@ -65,7 +65,7 @@ function watchOutputDirectory(outputDir: string, logService: ILogService, onChan
 }
 
 interface OutputChannel extends IOutputChannel {
-	readonly file: URI;
+	readonly file: URI | null;
 	readonly onDidAppendedContent: Event<void>;
 	readonly onDispose: Event<void>;
 	loadModel(): Promise<ITextModel>;
@@ -83,14 +83,14 @@ abstract class AbstractFileOutputChannel extends Disposable implements OutputCha
 
 	private readonly mimeType: string;
 	protected modelUpdater: RunOnceScheduler;
-	protected model: ITextModel;
+	protected model: ITextModel | null;
 	readonly file: URI;
 
 	protected startOffset: number = 0;
 	protected endOffset: number = 0;
 
 	constructor(
-		readonly outputChannelDescriptor: IOutputChannelDescriptor,
+		readonly outputChannelDescriptor: IFileOutputChannelDescriptor,
 		private readonly modelUri: URI,
 		protected fileService: IFileService,
 		protected modelService: IModelService,
@@ -154,7 +154,7 @@ abstract class AbstractFileOutputChannel extends Disposable implements OutputCha
 	abstract append(message: string);
 
 	protected onModelCreated(model: ITextModel) { }
-	protected onModelWillDispose(model: ITextModel) { }
+	protected onModelWillDispose(model: ITextModel | null) { }
 	protected onUpdateModelCancelled() { }
 	protected updateModel() { }
 
@@ -176,15 +176,14 @@ class OutputChannelBackedByFile extends AbstractFileOutputChannel implements Out
 	private readonly rotatingFilePath: string;
 
 	constructor(
-		outputChannelDescriptor: IOutputChannelDescriptor,
-		outputDir: string,
+		outputChannelDescriptor: IFileOutputChannelDescriptor,
 		modelUri: URI,
 		@IFileService fileService: IFileService,
 		@IModelService modelService: IModelService,
 		@IModeService modeService: IModeService,
 		@ILogService logService: ILogService
 	) {
-		super({ ...outputChannelDescriptor, file: URI.file(join(outputDir, `${outputChannelDescriptor.id}.log`)) }, modelUri, fileService, modelService, modeService);
+		super(outputChannelDescriptor, modelUri, fileService, modelService, modeService);
 
 		// Use one rotating file to check for main file reset
 		this.appender = new OutputAppender(this.id, this.file.fsPath);
@@ -262,7 +261,7 @@ class OutputChannelBackedByFile extends AbstractFileOutputChannel implements Out
 		}
 	}
 
-	private onFileChangedInOutputDirector(eventType: string, fileName: string): void {
+	private onFileChangedInOutputDirector(eventType: string, fileName?: string): void {
 		// Check if rotating file has changed. It changes only when the main file exceeds its limit.
 		if (this.rotatingFilePath === fileName) {
 			this.resettingDelayer.trigger(() => this.resetModel());
@@ -286,11 +285,11 @@ class FileOutputChannel extends AbstractFileOutputChannel implements OutputChann
 	private readonly fileHandler: FileListener;
 
 	private updateInProgress: boolean = false;
-	private etag: string = '';
-	private loadModelPromise: Promise<ITextModel> = Promise.resolve(undefined);
+	private etag: string | undefined = '';
+	private loadModelPromise: Promise<ITextModel> | null = null;
 
 	constructor(
-		outputChannelDescriptor: IOutputChannelDescriptor,
+		outputChannelDescriptor: IFileOutputChannelDescriptor,
 		modelUri: URI,
 		@IFileService fileService: IFileService,
 		@IModelService modelService: IModelService,
@@ -314,7 +313,8 @@ class FileOutputChannel extends AbstractFileOutputChannel implements OutputChann
 	}
 
 	clear(till?: number): void {
-		this.loadModelPromise.then(() => {
+		const loadModelPromise: Promise<any> = this.loadModelPromise ? this.loadModelPromise : Promise.resolve();
+		loadModelPromise.then(() => {
 			super.clear(till);
 			this.update();
 		});
@@ -344,7 +344,7 @@ class FileOutputChannel extends AbstractFileOutputChannel implements OutputChann
 		this.fileHandler.watch(this.etag);
 	}
 
-	protected onModelWillDispose(model: ITextModel): void {
+	protected onModelWillDispose(model: ITextModel | null): void {
 		this.fileHandler.unwatch();
 	}
 
@@ -353,13 +353,15 @@ class FileOutputChannel extends AbstractFileOutputChannel implements OutputChann
 	}
 
 	update(size?: number): void {
-		if (!this.updateInProgress) {
-			this.updateInProgress = true;
-			if (isNumber(size) && this.endOffset > size) { // Reset - Content is removed
-				this.startOffset = this.endOffset = 0;
-				this.model.setValue('');
+		if (this.model) {
+			if (!this.updateInProgress) {
+				this.updateInProgress = true;
+				if (isNumber(size) && this.endOffset > size) { // Reset - Content is removed
+					this.startOffset = this.endOffset = 0;
+					this.model.setValue('');
+				}
+				this.modelUpdater.schedule();
 			}
-			this.modelUpdater.schedule();
 		}
 	}
 }
@@ -370,7 +372,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 
 	private channels: Map<string, OutputChannel> = new Map<string, OutputChannel>();
 	private activeChannelIdInStorage: string;
-	private activeChannel: IOutputChannel;
+	private activeChannel: IOutputChannel | null;
 	private readonly outputDir: string;
 
 	private readonly _onActiveOutputChannel = new Emitter<string>();
@@ -392,7 +394,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		@IContextKeyService private readonly contextKeyService: IContextKeyService,
 	) {
 		super();
-		this.activeChannelIdInStorage = this.storageService.get(OUTPUT_ACTIVE_CHANNEL_KEY, StorageScope.WORKSPACE, null);
+		this.activeChannelIdInStorage = this.storageService.get(OUTPUT_ACTIVE_CHANNEL_KEY, StorageScope.WORKSPACE, '');
 		this.outputDir = join(environmentService.logsPath, `output_${windowService.getCurrentWindowId()}_${toLocalISOString(new Date()).replace(/-|:|\.\d+Z$/g, '')}`);
 
 		// Register as text model content provider for output
@@ -419,7 +421,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		this._register(this.storageService.onWillSaveState(() => this.saveState()));
 	}
 
-	provideTextContent(resource: URI): Promise<ITextModel> {
+	provideTextContent(resource: URI): Promise<ITextModel> | null {
 		const channel = <OutputChannel>this.getChannel(resource.path);
 		if (channel) {
 			return channel.loadModel();
@@ -447,15 +449,15 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		return promise.then(() => this._onActiveOutputChannel.fire(id));
 	}
 
-	getChannel(id: string): IOutputChannel {
-		return this.channels.get(id);
+	getChannel(id: string): IOutputChannel | null {
+		return this.channels.get(id) || null;
 	}
 
 	getChannelDescriptors(): IOutputChannelDescriptor[] {
 		return Registry.as<IOutputChannelRegistry>(Extensions.OutputChannels).getChannels();
 	}
 
-	getActiveChannel(): IOutputChannel {
+	getActiveChannel(): IOutputChannel | null {
 		return this.activeChannel;
 	}
 
@@ -469,7 +471,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		}
 	}
 
-	private onDidPanelOpen(panel: IPanel, preserveFocus: boolean): Promise<void> {
+	private onDidPanelOpen(panel: IPanel | null, preserveFocus: boolean): Promise<void> {
 		if (panel && panel.getId() === OUTPUT_PANEL_ID) {
 			this._outputPanel = <OutputPanel>this.panelService.getActivePanel();
 			if (this.activeChannel) {
@@ -506,7 +508,9 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 					this.showChannel(channel.id, true);
 				} else {
 					this.activeChannel = channel;
-					this._onActiveOutputChannel.fire(channel ? channel.id : undefined);
+					if (this.activeChannel) {
+						this._onActiveOutputChannel.fire(this.activeChannel.id);
+					}
 				}
 			}
 			Registry.as<IOutputChannelRegistry>(Extensions.OutputChannels).removeChannel(id);
@@ -528,7 +532,8 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 			return this.instantiationService.createInstance(FileOutputChannel, channelData, uri);
 		}
 		try {
-			return this.instantiationService.createInstance(OutputChannelBackedByFile, { id, label: channelData ? channelData.label : '' }, this.outputDir, uri);
+			const channelDescriptor: IFileOutputChannelDescriptor = { id, label: channelData ? channelData.label : '', log: false, file: URI.file(join(this.outputDir, `${id}.log`)) };
+			return this.instantiationService.createInstance(OutputChannelBackedByFile, channelDescriptor, uri);
 		} catch (e) {
 			// Do not crash if spdlog rotating logger cannot be loaded (workaround for https://github.com/Microsoft/vscode/issues/47883)
 			this.logService.error(e);
@@ -584,7 +589,7 @@ export class LogContentProvider {
 	) {
 	}
 
-	provideTextContent(resource: URI): Promise<ITextModel> {
+	provideTextContent(resource: URI): Promise<ITextModel> | null {
 		if (resource.scheme === LOG_SCHEME) {
 			let channel = this.getChannel(resource);
 			if (channel) {
@@ -594,7 +599,7 @@ export class LogContentProvider {
 		return null;
 	}
 
-	private getChannel(resource: URI): OutputChannel {
+	private getChannel(resource: URI): OutputChannel | undefined {
 		const channelId = resource.path;
 		let channel = this.channels.get(channelId);
 		if (!channel) {
@@ -624,9 +629,9 @@ class BufferredOutputChannel extends Disposable implements OutputChannel {
 	readonly onDispose: Event<void> = this._onDispose.event;
 
 	private modelUpdater: RunOnceScheduler;
-	private model: ITextModel;
+	private model: ITextModel | null;
 	private readonly bufferredContent: BufferedContent;
-	private lastReadId: number = undefined;
+	private lastReadId: number | undefined = undefined;
 
 	constructor(
 		protected readonly outputChannelIdentifier: IOutputChannelDescriptor,
@@ -731,7 +736,9 @@ class BufferedContent {
 		while (this.length > MAX_OUTPUT_LENGTH) {
 			this.dataIds.shift();
 			const removed = this.data.shift();
-			this.length -= removed.length;
+			if (removed) {
+				this.length -= removed.length;
+			}
 		}
 	}