fixes microsoft#103169

Author: sbatten

src/vs/base/browser/ui/contextview/contextview.ts

@@ -216,6 +216,10 @@ export class ContextView extends Disposable {
 		}
 	}
 
+	getViewElement(): HTMLElement {
+		return this.view;
+	}
+
 	layout(): void {
 		if (!this.isVisible()) {
 			return;

src/vs/editor/contrib/contextmenu/contextmenu.ts

@@ -49,7 +49,14 @@ export class ContextMenuController implements IEditorContribution {
 		this._toDispose.add(this._editor.onContextMenu((e: IEditorMouseEvent) => this._onContextMenu(e)));
 		this._toDispose.add(this._editor.onMouseWheel((e: IMouseWheelEvent) => {
 			if (this._contextMenuIsBeingShownCount > 0) {
-				this._contextViewService.hideContextView();
+				const view = this._contextViewService.getContextViewElement();
+				const target = e.srcElement as HTMLElement;
+
+				// Event triggers on shadow root host first
+				// Check if the context view is under this host before hiding it #103169
+				if (!(target.shadowRoot && dom.getShadowRoot(view) === target.shadowRoot)) {
+					this._contextViewService.hideContextView();
+				}
 			}
 		}));
 		this._toDispose.add(this._editor.onKeyDown((e: IKeyboardEvent) => {

src/vs/platform/contextview/browser/contextView.ts

@@ -17,6 +17,7 @@ export interface IContextViewService extends IContextViewProvider {
 
 	showContextView(delegate: IContextViewDelegate, container?: HTMLElement, shadowRoot?: boolean): IDisposable;
 	hideContextView(data?: any): void;
+	getContextViewElement(): HTMLElement;
 	layout(): void;
 	anchorAlignment?: AnchorAlignment;
 }

src/vs/platform/contextview/browser/contextViewService.ts

@@ -58,6 +58,10 @@ export class ContextViewService extends Disposable implements IContextViewServic
 		return disposable;
 	}
 
+	getContextViewElement(): HTMLElement {
+		return this.contextView.getViewElement();
+	}
+
 	layout(): void {
 		this.contextView.layout();
 	}