Firefox is terminated during Drag & Drop due to protocol error - mutter selects 'Ask' method
When pasting an image from Nautilus to Firefox (to http://onpaste.com/ site) and user press 'ALT', a question mark is shown and Mutter selects 'ASK' D&D method. When Drop is performed Firefox is terminated with protocol error.
But Firefox states it doesn't want the 'ASK' method:
[2618374.932] firstname.lastname@example.org(4) [2618375.011] -> email@example.com_actions(7, 2) [2618375.020] -> firstname.lastname@example.org(25200, "text/plain")
This is Mutter bug only, KWin works as expected.