Ticket #7694: 7694_2.patch

_source/plugins/styles/plugin.js

@@ -815 +815 @@
         {
                 var root = range.getCommonAncestor( true, true ),
                         element = root.getAscendant( this.element, true );
-                element && setupElement( element, this );
+                element && !element.isReadOnly() && setupElement( element, this );
         }
 
         function removeObjectStyle( range )
@@ -872 +872 @@
 
                 while ( ( block = iterator.getNextParagraph() ) )               // Only one =
                 {
-                        var newBlock = getElement( this, doc, block );
-                        replaceBlock( block, newBlock );
-                }
+                        if ( !block.isReadOnly() )
+                        {
+                                var newBlock = getElement( this, doc, block );
+                                replaceBlock( block, newBlock );
+                        }
+                }
 
                 range.moveToBookmark( bookmark );
         }