Fix scroll position not being restored on release notes

Fixes #45571

src/vs/workbench/parts/webview/electron-browser/webview-pre.js

@@ -99,7 +99,7 @@
 			return;
 		}
 
-		const progress = event.target.body.scrollTop / event.target.body.clientHeight;
+		const progress = event.currentTarget.scrollY / event.target.body.clientHeight;
 		if (isNaN(progress)) {
 			return;
 		}
@@ -312,10 +312,10 @@
 			var setInitialScrollPosition;
 			if (firstLoad) {
 				firstLoad = false;
-				setInitialScrollPosition = (body) => {
+				setInitialScrollPosition = (body, window) => {
 					if (!isNaN(initData.initialScrollProgress)) {
 						if (body.scrollTop === 0) {
-							body.scrollTop = body.clientHeight * initData.initialScrollProgress;
+							window.scroll(0, body.clientHeight * initData.initialScrollProgress);
 						}
 					}
 				};
@@ -323,7 +323,7 @@
 				const scrollY = frame && frame.contentDocument && frame.contentDocument.body ? frame.contentDocument.body.scrollTop : 0;
 				setInitialScrollPosition = (body) => {
 					if (body.scrollTop === 0) {
-						body.scrollTop = scrollY;
+						window.scroll(0, scrollY);
 					}
 				};
 			}
@@ -360,7 +360,7 @@
 				if (contentDocument.body) {
 					// Workaround for https://github.com/Microsoft/vscode/issues/12865
 					// check new scrollTop and reset if neccessary
-					setInitialScrollPosition(contentDocument.body);
+					setInitialScrollPosition(contentDocument.body, contentWindow);
 
 					// Bubble out link clicks
 					contentDocument.body.addEventListener('click', handleInnerClick);

src/vs/workbench/parts/webview/electron-browser/webviewEditor.ts

@@ -184,14 +184,13 @@ export class WebviewEditor extends BaseWebviewEditor {
 	private updateWebview(input: WebviewEditorInput) {
 		const webview = this.getWebview(input);
 		input.claimWebview(this);
-		webview.options = {
+		webview.update(input.html, {
 			allowScripts: input.options.enableScripts,
 			allowSvgs: true,
 			enableWrappedPostMessage: true,
 			useSameOriginForRoot: false,
 			localResourceRoots: input.options.localResourceRoots || this.getDefaultLocalResourceRoots()
-		};
-		input.html = input.html;
+		});
 
 		if (this._webviewContent) {
 			this._webviewContent.style.visibility = 'visible';

src/vs/workbench/parts/webview/electron-browser/webviewElement.ts

@@ -267,6 +267,16 @@ export class WebviewElement extends Disposable {
 		});
 	}
 
+	public update(value: string, options: WebviewOptions) {
+		this._contents = value;
+		this._options = options;
+		this._send('content', {
+			contents: this._contents,
+			options: this._options,
+			state: this._state
+		});
+	}
+
 	public set baseUrl(value: string) {
 		this._send('baseUrl', value);
 	}