Split Editor Windows: Warning appears multiple times

Steps to reproduce:

• create Qt Quick Application from template (, >= Qt5.4, check the 'with ui.qml file')
• double click on the created ui.qml file
  • QC switches to Design mode
• switch back to Edit mode
  • QC should display a warning regarding 'file should only get edited in Design mode' (but anyhow: ui.qml files are likely to get edited manually as well)
• click the Split Window icon and / or the Split Window Side by Side
• start editing something inside any of the editors
  • the warning mentioned above is added again to all editors
  • if you opened 2 additional editors you'll get the warning twice in all respective editors