Open in background hotkey should only activate if cursor is at end of line (fixes #14350)

src/vs/base/parts/quickopen/browser/quickOpenWidget.ts

@@ -152,6 +152,7 @@ export class QuickOpenWidget implements IModelProvider {
 
 				DOM.addDisposableListener(this.inputBox.inputElement, DOM.EventType.KEY_DOWN, (e: KeyboardEvent) => {
 					const keyboardEvent: StandardKeyboardEvent = new StandardKeyboardEvent(e);
+					const shouldOpenInBackground = this.shouldOpenInBackground(keyboardEvent);
 
 					// Do not handle Tab: It is used to navigate between elements without mouse
 					if (keyboardEvent.keyCode === KeyCode.Tab) {
@@ -165,13 +166,13 @@ export class QuickOpenWidget implements IModelProvider {
 						this.navigateInTree(keyboardEvent.keyCode, keyboardEvent.shiftKey);
 					}
 
-					// Select element on Enter
-					else if (keyboardEvent.keyCode === KeyCode.Enter || keyboardEvent.keyCode === KeyCode.RightArrow) {
+					// Select element on Enter or on Arrow-Right if we are at the end of the input
+					else if (keyboardEvent.keyCode === KeyCode.Enter || shouldOpenInBackground) {
 						DOM.EventHelper.stop(e, true);
 
 						const focus = this.tree.getFocus();
 						if (focus) {
-							this.elementSelected(focus, e, keyboardEvent.keyCode === KeyCode.RightArrow ? Mode.OPEN_IN_BACKGROUND : Mode.OPEN);
+							this.elementSelected(focus, e, shouldOpenInBackground ? Mode.OPEN_IN_BACKGROUND : Mode.OPEN);
 						}
 					}
 
@@ -304,6 +305,18 @@ export class QuickOpenWidget implements IModelProvider {
 		return this.builder.getHTMLElement();
 	}
 
+	private shouldOpenInBackground(e: StandardKeyboardEvent): boolean {
+		if (e.keyCode !== KeyCode.RightArrow) {
+			return false; // only for right arrow
+		}
+
+		if (e.metaKey || e.ctrlKey || e.shiftKey || e.altKey) {
+			return false; // no modifiers allowed
+		}
+
+		return this.inputBox.inputElement.selectionStart === this.inputBox.value.length; // only when cursor is at the end of the input field value
+	}
+
 	private onType(): void {
 		const value = this.inputBox.value;