Typing ".." in the (simple) Open File dialog has strange behaviour (microsoft#235746)

Fixes microsoft#154642

Author: alexr00

src/vs/workbench/services/dialogs/browser/simpleFileDialog.ts

@@ -862,6 +862,8 @@ export class SimpleFileDialog extends Disposable implements ISimpleFileDialog {
 	private async updateItems(newFolder: URI, force: boolean = false, trailing?: string): Promise<boolean> {
 		this.busy = true;
 		this.autoCompletePathSegment = '';
+		const wasDotDot = trailing === '..';
+		trailing = wasDotDot ? undefined : trailing;
 		const isSave = !!trailing;
 		let result = false;
 
@@ -892,7 +894,7 @@ export class SimpleFileDialog extends Disposable implements ISimpleFileDialog {
 				this.filePickBox.items = items;
 
 				// the user might have continued typing while we were updating. Only update the input box if it doesn't match the directory.
-				if (!equalsIgnoreCase(this.filePickBox.value, newValue) && force) {
+				if (!equalsIgnoreCase(this.filePickBox.value, newValue) && (force || wasDotDot)) {
 					this.filePickBox.valueSelection = [0, this.filePickBox.value.length];
 					this.insertText(newValue, newValue);
 				}