handle no readme. call super set input.

fixes #8830

src/vs/workbench/parts/extensions/electron-browser/extensionEditor.ts

@@ -116,7 +116,6 @@ export class ExtensionEditor extends BaseEditor {
 	setInput(input: ExtensionsInput, options: EditorOptions): TPromise<void> {
 		this.transientDisposables = dispose(this.transientDisposables);
 
-		let promise = TPromise.as(null);
 		const extension = input.extension;
 
 		this.icon.style.backgroundImage = `url("${ extension.iconUrl }")`;
@@ -152,10 +151,11 @@ export class ExtensionEditor extends BaseEditor {
 		this.transientDisposables.push(enableAction, updateAction, installAction);
 
 		this.body.innerHTML = '';
-		addClass(this.body, 'loading');
+		let promise: TPromise<any> = super.setInput(input, options);
 
 		if (extension.readmeUrl) {
-			promise = super.setInput(input, options)
+			promise = promise
+				.then(() => addClass(this.body, 'loading'))
 				.then(() => this.requestService.makeRequest({ url: extension.readmeUrl }))
 				.then(response => response.responseText)
 				.then(marked.parse)
@@ -174,6 +174,10 @@ export class ExtensionEditor extends BaseEditor {
 				})
 				.then(null, () => null)
 				.then(() => removeClass(this.body, 'loading'));
+		} else {
+			promise = promise
+				.then(() => append(this.body, $('p')))
+				.then(p => p.textContent = localize('noReadme', "No README available."));
 		}
 
 		this.transientDisposables.push(toDisposable(() => promise.cancel()));

src/vs/workbench/parts/extensions/electron-browser/media/extensionEditor.css

@@ -103,4 +103,8 @@
 .extension-editor > .body {
 	height: calc(100% - 168px);
 	overflow: hidden;
+}
+
+.extension-editor > .body > p {
+	margin: 20px;
 }
\ No newline at end of file