Merge branch 't/10373'

CHANGES.md

@@ -5,6 +5,7 @@
 
 Fixed Issues:
 
+* [#10373](http://dev.ckeditor.com/ticket/10373): Fixed: Context menu items can be dragged into the editor.
 * [#16728](http://dev.ckeditor.com/ticket/16728): [IE] Fixed: [Copy Formatting](http://ckeditor.com/addon/copyformatting) breaks editor in Quirks Mode.
 * [#16753](http://dev.ckeditor.com/ticket/16753): Fixed: `element.setSize` sets wrong editor's dimensions if border's width is in fraction of pixels.
 

plugins/menu/plugin.js

@@ -92,7 +92,8 @@ CKEDITOR.plugins.add( 'menu', {
 		' aria-describedby="{id}_description"' +
 		' aria-haspopup="{hasPopup}"' +
 		' aria-disabled="{disabled}"' +
-		' {ariaChecked}';
+		' {ariaChecked}' +
+		' draggable="false"';
 
 	// Some browsers don't cancel key events in the keydown but in the
 	// keypress.

tests/plugins/menu/manual/drag.html

@@ -0,0 +1,7 @@
+<textarea id="editor1" cols="10" rows="10">
+	<p>This is some text.</p>
+</textarea>
+
+<script>
+	CKEDITOR.replace( 'editor1' );
+</script>

tests/plugins/menu/manual/drag.md

@@ -0,0 +1,8 @@
+@bender-tags: 10373, tc, 4.6.2
+@bender-ui: collapsed
+@bender-ckeditor-plugins: wysiwygarea, toolbar, clipboard, contextmenu
+
+1. Right-click on the editable area to invoke a context menu.
+2. Try to drag the menu content (e.g. "Paste") into the editable.
+
+**Expected:** Dragging menu contents into the editable should be impossible.