Markdown preview cannot be resized anymore (fixes #5833)

src/vs/base/browser/builder.ts

@@ -36,6 +36,7 @@ export interface QuickBuilder {
 	(): Builder;
 	(builders: Builder[]): Builder;
 	(element: HTMLElement): Builder;
+	(element: HTMLElement[]): Builder;
 	(window: Window): Builder;
 	(htmlOrQuerySyntax: string): Builder; // Or, MultiBuilder
 	(name: string, args?: any, fn?: (builder: Builder) => any): Builder;

src/vs/base/browser/dom.ts

@@ -979,3 +979,7 @@ export function removeTabIndexAndUpdateFocus(node: HTMLElement): void {
 
 	node.removeAttribute('tabindex');
 }
+
+export function getElementsByTagName(tag: string): HTMLElement[] {
+	return Array.prototype.slice.call(document.getElementsByTagName(tag), 0);
+}
\ No newline at end of file

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

@@ -108,6 +108,8 @@ export class Sash extends EventEmitter {
 			return;
 		}
 
+		$(DOM.getElementsByTagName('iframe')).style('pointer-events', 'none'); // disable mouse events on iframes as long as we drag the sash
+
 		let mouseDownEvent = new StandardMouseEvent(e);
 		let startX = mouseDownEvent.posx;
 		let startY = mouseDownEvent.posy;
@@ -150,6 +152,8 @@ export class Sash extends EventEmitter {
 
 			$window.off('mousemove');
 			document.body.classList.remove(containerCssClass);
+
+			$(DOM.getElementsByTagName('iframe')).style('pointer-events', 'auto');
 		});
 
 		document.body.classList.add(containerCssClass);