force primary click on dropdowns (microsoft#153176)

fixes microsoft#151064

Author: sbatten

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

@@ -56,8 +56,10 @@ export class BaseDropdown extends ActionRunner {
 
 		for (const event of [EventType.MOUSE_DOWN, GestureEventType.Tap]) {
 			this._register(addDisposableListener(this._label, event, e => {
-				if (e instanceof MouseEvent && e.detail > 1) {
-					return; // prevent multiple clicks to open multiple context menus (https://github.com/microsoft/vscode/issues/41363)
+				if (e instanceof MouseEvent && (e.detail > 1 || e.button !== 0)) {
+					// prevent right click trigger to allow separate context menu (https://github.com/microsoft/vscode/issues/151064)
+					// prevent multiple clicks to open multiple context menus (https://github.com/microsoft/vscode/issues/41363)
+					return;
 				}
 
 				if (this.visible) {