Fix diff of large descriptions

Signed-off-by: Julius Härtl <jus@bitgrid.net>

css/activity.css

@@ -8,6 +8,11 @@
 	text-decoration: none;
 }
 
+.activitymessage .visualdiff {
+	overflow: scroll;
+	max-height: 200px;
+}
+
 .activityTabView .avatardiv-container {
 	display: inline-block;
 	bottom: -3px;

lib/Activity/DeckProvider.php

@@ -276,7 +276,8 @@ class DeckProvider implements IProvider {
 	private function parseParamForChanges($subjectParams, $params, $event) {
 		if (array_key_exists('diff', $subjectParams) && $subjectParams['diff']) {
 			$diff = new Diff();
-			$event->setMessage($subjectParams['after']);
+			// Don't add diff as message since we are limited to 255 chars here
+			//$event->setMessage($subjectParams['after']);
 			$event->setParsedMessage('<pre class="visualdiff">' . $diff->render($subjectParams['before'], $subjectParams['after']) . '</pre>');
 			return $params;
 		}