Missing context menu for text field

[Wiktor Walc]

There is no context menu for some form elements. Strangely it looks like it is something that was fixed in 3.4: #6046 but the fact is that the following test case worked fine until 3.3.1

Steps to reproduce

• start with the following source:

  <form action="action" name="name">
  	<br />
  	<input name="name" type="text" value="value" />&nbsp;</form>
  

• right-click on the text field, the result is on the screenshot

Confirmed in FF 3.6.13 and IE8. Note that when inserting the element for the first time in wysiwyg mode, the context menu contains the right items, after switching to source mode and back, the context menu is gone.

[Alfonso Martínez de Lizarrondo]

dup of #6646