Fixes microsoft#158948 (microsoft#164439)

Author: hediet

src/vs/workbench/contrib/mergeEditor/browser/view/mergeEditor.ts

@@ -199,7 +199,15 @@ export class MergeEditor extends AbstractTextEditor<IMergeEditorViewState> {
 		const inputModel = await input.resolve();
 		const model = inputModel.model;
 
-		const viewModel = new MergeEditorViewModel(model, this.input1View, this.input2View, this.inputResultView, this.baseView, this.showNonConflictingChanges, this.configurationService);
+		const viewModel = this.instantiationService.createInstance(
+			MergeEditorViewModel,
+			model,
+			this.input1View,
+			this.input2View,
+			this.inputResultView,
+			this.baseView,
+			this.showNonConflictingChanges,
+		);
 
 
 		model.telemetry.reportMergeEditorOpened({

src/vs/workbench/contrib/mergeEditor/browser/view/viewModel.ts

@@ -8,7 +8,9 @@ import { Disposable } from 'vs/base/common/lifecycle';
 import { derived, derivedObservableWithWritableCache, IObservable, IReader, ITransaction, observableFromEvent, observableValue, transaction } from 'vs/base/common/observable';
 import { Range } from 'vs/editor/common/core/range';
 import { ScrollType } from 'vs/editor/common/editorCommon';
+import { localize } from 'vs/nls';
 import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
+import { INotificationService } from 'vs/platform/notification/common/notification';
 import { LineRange } from 'vs/workbench/contrib/mergeEditor/browser/model/lineRange';
 import { MergeEditorModel } from 'vs/workbench/contrib/mergeEditor/browser/model/mergeEditorModel';
 import { ModifiedBaseRange, ModifiedBaseRangeState } from 'vs/workbench/contrib/mergeEditor/browser/model/modifiedBaseRange';
@@ -29,7 +31,8 @@ export class MergeEditorViewModel extends Disposable {
 		public readonly resultCodeEditorView: ResultCodeEditorView,
 		public readonly baseCodeEditorView: IObservable<BaseCodeEditorView | undefined>,
 		public readonly showNonConflictingChanges: IObservable<boolean>,
-		@IConfigurationService public readonly configurationService: IConfigurationService,
+		@IConfigurationService private readonly configurationService: IConfigurationService,
+		@INotificationService private readonly notificationService: INotificationService
 	) {
 		super();
 
@@ -220,6 +223,7 @@ export class MergeEditorViewModel extends Disposable {
 	public toggleActiveConflict(inputNumber: 1 | 2): void {
 		const activeModifiedBaseRange = this.activeModifiedBaseRange.get();
 		if (!activeModifiedBaseRange) {
+			this.notificationService.error(localize('noConflictMessage', "There is currently no conflict focused that can be toggled."));
 			return;
 		}
 		transaction(tx => {