Ticket #3257: 3257_2.patch

_source/plugins/list/plugin.js

@@ -234 +234 @@
                 newList.listNode.replace( groupObj.root );
         }
 
+        var headerTagRegex = /^h[1-6]$/;
+
         function createList( editor, groupObj, listsCreated )
         {
                 var contents = groupObj.contents,
@@ -285 +287 @@
                 {
                         var contentBlock = listContents.shift(),
                                 listItem = doc.createElement( 'li' );
-                        contentBlock.moveChildren( listItem );
-                        contentBlock.remove();
+
+                        // Preserve heading structure when converting to list item. (#5271)
+                        if ( headerTagRegex.test( contentBlock.getName() ) )
+                                contentBlock.appendTo( listItem );
+                        else
+                        {
+                                contentBlock.copyAttributes( listItem );
+                                contentBlock.moveChildren( listItem );
+                                contentBlock.remove();
+                        }
+
                         listItem.appendTo( listNode );
 
                         // Append a bogus BR to force the LI to render at full height