keep custom editor when editor assocaition is available.

src/vs/workbench/contrib/customEditor/browser/customEditorInputFactory.ts

@@ -18,6 +18,7 @@ import { ICustomEditorService } from 'vs/workbench/contrib/customEditor/common/c
 import { Schemas } from 'vs/base/common/network';
 import { isEqual } from 'vs/base/common/resources';
 import { NotebookEditorInput } from 'vs/workbench/contrib/notebook/common/notebookEditorInput';
+import { IEditorResolverService } from 'vs/workbench/services/editor/common/editorResolverService';
 
 export interface CustomDocumentBackupData extends IWorkingCopyBackupMeta {
 	readonly viewType: string;
@@ -56,6 +57,7 @@ export class CustomEditorInputSerializer extends WebviewEditorInputSerializer {
 		@IWebviewWorkbenchService webviewWorkbenchService: IWebviewWorkbenchService,
 		@IInstantiationService private readonly _instantiationService: IInstantiationService,
 		@IWebviewService private readonly _webviewService: IWebviewService,
+		@IEditorResolverService private readonly _editorResolverService: IEditorResolverService
 	) {
 		super(webviewWorkbenchService);
 	}
@@ -90,7 +92,10 @@ export class CustomEditorInputSerializer extends WebviewEditorInputSerializer {
 	): CustomEditorInput {
 		const data = this.fromJson(JSON.parse(serializedEditorInput));
 		if (data.viewType === 'jupyter.notebook.ipynb') {
-			return NotebookEditorInput.create(this._instantiationService, data.editorResource, 'jupyter-notebook', { _backupId: data.backupId, startDirty: data.dirty }) as any;
+			const editorAssociation = this._editorResolverService.getAssociationsForResource(data.editorResource);
+			if (!editorAssociation.find(association => association.viewType === 'jupyter.notebook.ipynb')) {
+				return NotebookEditorInput.create(this._instantiationService, data.editorResource, 'jupyter-notebook', { _backupId: data.backupId, startDirty: data.dirty }) as any;
+			}
 		}
 
 		const webview = reviveWebview(this._webviewService, data);
@@ -118,6 +123,7 @@ export class ComplexCustomWorkingCopyEditorHandler extends Disposable implements
 		@IInstantiationService private readonly _instantiationService: IInstantiationService,
 		@IWorkingCopyEditorService private readonly _workingCopyEditorService: IWorkingCopyEditorService,
 		@IWorkingCopyBackupService private readonly _workingCopyBackupService: IWorkingCopyBackupService,
+		@IEditorResolverService private readonly _editorResolverService: IEditorResolverService,
 		@IWebviewService private readonly _webviewService: IWebviewService,
 		@ICustomEditorService _customEditorService: ICustomEditorService // DO NOT REMOVE (needed on startup to register overrides properly)
 	) {
@@ -164,7 +170,10 @@ export class ComplexCustomWorkingCopyEditorHandler extends Disposable implements
 
 				const backupData = backup.meta;
 				if (backupData.viewType === 'jupyter.notebook.ipynb') {
-					return NotebookEditorInput.create(this._instantiationService, URI.revive(backupData.editorResource), 'jupyter-notebook', { startDirty: !!backupData.backupId, _backupId: backupData.backupId, _workingCopy: workingCopy }) as any;
+					const editorAssociation = this._editorResolverService.getAssociationsForResource(URI.revive(backupData.editorResource));
+					if (!editorAssociation.find(association => association.viewType === 'jupyter.notebook.ipynb')) {
+						return NotebookEditorInput.create(this._instantiationService, URI.revive(backupData.editorResource), 'jupyter-notebook', { startDirty: !!backupData.backupId, _backupId: backupData.backupId, _workingCopy: workingCopy }) as any;
+					}
 				}
 
 				const id = backupData.webview.id;