The diagram macro shows the "Create diagram" button even after the diagram was created

Follow this steps to reproduce:

• Edit a wiki page with the WYSIWYG editor
• Insert a diagram macro, keeping the default parameter values
• Save

or simply

• Edit a wiki page in Wiki editor mode
• Insert

  {{diagram /}}

  somewhere

• Save

then, from view mode

• Click on the "Create diagram" button
• Add some shapes
• Save the diagram
• Go back to the initial page

The "Create diagram" button is still displayed although the diagram was created.