PLT-5188: Reinstate delete option on system messages. (#5113)

* PLT-5188: Reinstate delete option on system messages.

* Fix styling.

* Fix empty hover box.

webapp/components/post_view/components/post_info.jsx

@@ -53,10 +53,8 @@ export default class PostInfo extends React.Component {
     }
 
     createDropdown() {
-        var post = this.props.post;
+        const post = this.props.post;
-
+        const isSystemMessage = PostUtils.isSystemMessage(post);
-        this.canDelete = PostUtils.canDeletePost(post);
-        this.canEdit = PostUtils.canEditPost(post, this.editDisableAction);
 
         if (post.state === Constants.POST_FAILED || post.state === Constants.POST_LOADING) {
             return '';
@@ -131,6 +129,7 @@ export default class PostInfo extends React.Component {
             }
         }
 
+        if (!isSystemMessage) {
             dropdownContents.push(
                 <li
                     key='copyLink'
@@ -147,6 +146,7 @@ export default class PostInfo extends React.Component {
                     </a>
                 </li>
             );
+        }
 
         if (this.canDelete) {
             dropdownContents.push(
@@ -267,6 +267,9 @@ export default class PostInfo extends React.Component {
         var commentCountText = this.props.commentCount;
         const flagIcon = Constants.FLAG_ICON_SVG;
 
+        this.canDelete = PostUtils.canDeletePost(post);
+        this.canEdit = PostUtils.canEditPost(post, this.editDisableAction);
+
         if (this.props.commentCount >= 1) {
             showCommentClass = ' icon--show';
         } else {
@@ -296,19 +299,22 @@ export default class PostInfo extends React.Component {
                     {this.createRemovePostButton()}
                 </li>
             );
-        } else if (!PostUtils.isSystemMessage(post)) {
+        } else {
+            const dropdown = this.createDropdown();
+            if (dropdown) {
                 options = (
                     <li className='col col__reply'>
                         <div
                             className='dropdown'
                             ref='dotMenu'
                         >
-                        {this.createDropdown()}
+                            {dropdown}
                         </div>
                         {comments}
                     </li>
                 );
             }
+        }
 
         let flag;
         let flagFunc;

webapp/sass/layout/_post.scss

@@ -518,6 +518,17 @@
     position: relative;
     word-wrap: break-word;
 
+    &.post--system {
+        .post__header {
+            .col__reply {
+                min-width: 0;
+            }
+            .dropdown {
+                margin-right: 0;
+            }
+        }
+    }
+
     &:hover {
         .dropdown,
         .comment-icon__container,