Reviewed by Dave Hyatt.

        Test cases added: none, doesn't affect layout

        - fixed <rdar://problem/4211999> Safari quits when click-drag-hold an image that is
        set to automatically change.

        * khtml/khtmlview.cpp:
        (KHTMLView::updateDragAndDrop):
        add missing nil check

WebKit:

        Reviewed by Dave Hyatt.

        - change related to <rdar://problem/4211999> Safari quits when click-drag-hold an image
        that is set to automatically change.

        * WebView.subproj/WebHTMLView.m:
        (-[NSArray namesOfPromisedFilesDroppedAtDestination:]):
        handle nil wrapper with ERROR and early return rather than ASSERT, since we now know
        of a way to reproduce this (written up as 4244861)


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@10471 268f45cc-cd09-0410-ab3c-d52691b4dbfc