Hide empty MessageActionBar on message edit history dialog

res/css/views/dialogs/_MessageEditHistoryDialog.pcss

@@ -74,13 +74,20 @@ limitations under the License.
         }
     }
 
-    .mx_MessageActionBar .mx_AccessibleButton {
-        display: flex;
-        align-items: center;
+    .mx_MessageActionBar {
+        &.mx_MessageActionBar--noButton {
+            /* Hide if neither redact nor view source button is rendered inside it */
+            display: none;
+        }
+
+        .mx_AccessibleButton {
+            display: flex;
+            align-items: center;
 
-        padding-inline-start: $spacing-8;
-        padding-inline-end: $spacing-8;
+            padding-inline-start: $spacing-8;
+            padding-inline-end: $spacing-8;
 
-        font-size: $font-15px;
+            font-size: $font-15px;
+        }
     }
 }

src/components/views/messages/EditHistoryMessage.tsx

@@ -141,9 +141,13 @@ export default class EditHistoryMessage extends React.PureComponent<IProps, ISta
             );
         }
 
+        const classes = classNames("mx_MessageActionBar", {
+            "mx_MessageActionBar--noButton": !SettingsStore.getValue("developerMode") && !redactButton,
+        });
+
         // disabled remove button when not allowed
         return (
-            <div className="mx_MessageActionBar">
+            <div className={classes}>
                 {redactButton}
                 {viewSourceButton}
             </div>