Bug 1232910

Description of problem:
Seems to occur every time (or nearly every time) I click and drag in Evolution on Rawhide (F23) at present:

evolution-3.17.2-1.fc23.x86_64
gtk3-3.17.3-1.fc23.x86_64

The system becomes unresponsive locally for several seconds (though I can ssh in), then Evolution crashes and I can resume using the system normally.

Version-Release number of selected component:
evolution-3.17.2-1.fc23

Additional info:
reporter:       libreport-2.6.0
backtrace_rating: 4
cmdline:        evolution
crash_function: g_type_check_instance_is_fundamentally_a
executable:     /usr/bin/evolution
global_pid:     7494
kernel:         4.1.0-0.rc7.git1.1.fc23.x86_64
runlevel:       N 5
type:           CCpp
uid:            1001

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 g_type_check_instance_is_fundamentally_a at gtype.c:4028
 #1 g_object_ref at gobject.c:3040
 #2 set_icon_helper at gtkdnd.c:3141
 #3 gtk_drag_begin_internal at gtkdnd.c:2520
 #4 gtk_drag_begin at gtkdnd.c:2662
 #5 WebKit::DragClient::startDrag at Source/WebKit/gtk/WebCoreSupport/DragClientGtk.cpp:86
 #6 WebCore::DragController::doSystemDrag at Source/WebCore/page/DragController.cpp:909
 #7 WebCore::DragController::startDrag at Source/WebCore/page/DragController.cpp:834
 #8 WebCore::EventHandler::handleDrag at Source/WebCore/page/EventHandler.cpp:3299
 #9 WebCore::EventHandler::handleMouseDraggedEvent at Source/WebCore/page/EventHandler.cpp:755