In fast/dom/Window/window-postmessage-clone.html the file input control is after the output console div, so if a platform uses a default font which is large enough, console output may push it out of the viewport. If that happens, the EventSender will not be able to drop files onto the file input control. This was discovered during the implementation of beginDragWithFiles for GTK+.
Created attachment 78178 [details] Patch
Comment on attachment 78178 [details] Patch Clearing flags on attachment: 78178 Committed r75219: <http://trac.webkit.org/changeset/75219>
All reviewed patches have been landed. Closing bug.
http://trac.webkit.org/changeset/75219 might have broken GTK Linux 32-bit Debug