fixes #13502

src/vs/workbench/parts/output/browser/output.contribution.ts

@@ -15,7 +15,7 @@ import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { IWorkbenchActionRegistry, Extensions as ActionExtensions } from 'vs/workbench/common/actionRegistry';
 import { OutputService } from 'vs/workbench/parts/output/browser/outputServices';
 import { ToggleOutputAction, ClearOutputAction } from 'vs/workbench/parts/output/browser/outputActions';
-import { OUTPUT_MODE_ID, OUTPUT_PANEL_ID, IOutputService } from 'vs/workbench/parts/output/common/output';
+import { OUTPUT_MODE_ID, OUTPUT_MIME, OUTPUT_PANEL_ID, IOutputService } from 'vs/workbench/parts/output/common/output';
 import panel = require('vs/workbench/browser/panel');
 import { EditorContextKeys } from 'vs/editor/common/editorCommon';
 import { CommandsRegistry, ICommandHandler } from 'vs/platform/commands/common/commands';
@@ -28,7 +28,8 @@ registerSingleton(IOutputService, OutputService);
 ModesRegistry.registerLanguage({
 	id: OUTPUT_MODE_ID,
 	extensions: [],
-	aliases: [null]
+	aliases: [null],
+	mimetypes: [OUTPUT_MIME]
 });
 
 // Register Output Panel

src/vs/workbench/parts/output/browser/outputEditorInput.ts

@@ -11,7 +11,7 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { RunOnceScheduler } from 'vs/base/common/async';
 import { EditorModel } from 'vs/workbench/common/editor';
 import { StringEditorInput } from 'vs/workbench/common/editor/stringEditorInput';
-import { OUTPUT_EDITOR_INPUT_ID, OUTPUT_PANEL_ID, IOutputEvent, OUTPUT_MODE_ID, IOutputService, MAX_OUTPUT_LENGTH, IOutputChannel } from 'vs/workbench/parts/output/common/output';
+import { OUTPUT_EDITOR_INPUT_ID, OUTPUT_PANEL_ID, IOutputEvent, OUTPUT_MIME, IOutputService, MAX_OUTPUT_LENGTH, IOutputChannel } from 'vs/workbench/parts/output/common/output';
 import { OutputPanel } from 'vs/workbench/parts/output/browser/outputPanel';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { IPanelService } from 'vs/workbench/services/panel/common/panelService';
@@ -49,7 +49,7 @@ export class OutputEditorInput extends StringEditorInput {
 		@IOutputService private outputService: IOutputService,
 		@IPanelService private panelService: IPanelService
 	) {
-		super(nls.localize('output', "Output"), outputChannel ? nls.localize('outputChannel', "for '{0}'", outputChannel.label) : '', '', OUTPUT_MODE_ID, true, instantiationService);
+		super(nls.localize('output', "Output"), outputChannel ? nls.localize('outputChannel', "for '{0}'", outputChannel.label) : '', '', OUTPUT_MIME, true, instantiationService);
 
 		this.bufferedOutput = '';
 		this.toDispose = [];

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

@@ -11,6 +11,11 @@ import { createDecorator } from 'vs/platform/instantiation/common/instantiation'
 import { IEditor } from 'vs/platform/editor/common/editor';
 import { RawContextKey } from 'vs/platform/contextkey/common/contextkey';
 
+/**
+ * Mime type used by the output editor.
+ */
+export const OUTPUT_MIME = 'text/x-code-output';
+
 /**
  * Id used by the output editor.
  */