Fedora bug with a couple of duplicates: https://bugzilla.redhat.com/show_bug.cgi?id=540129 

I looked at this briefly and couldn't see anything obvious - reproduction instructions would be incredibly useful.

just happened to me with mutter.

mutter:ERROR:core/boxes.c:1161:meta_rectangle_edge_aligns: code should not be reached

was moving a newly created window (tvtime), but i cannot reproduce it.

sorry, forgot to add the last messages in the log:


Window manager warning: Buggy client sent a _NET_ACTIVE_WINDOW message with a timestamp of 0 for 0x2a00001 (tvtime)
Window manager warning: meta_window_activate called by a pager with a 0 timestamp; the pager needs to be fixed.
**
mutter:ERROR:core/boxes.c:1161:meta_rectangle_edge_aligns: code should not be reached
Shell killed with signal 6

Created attachment 153369 [details] [review]
Fix crash when struts change during grab operation

Since meta_workspace_invalidate_work_area() frees the edges
workspace->screen_edges and workspace->monitor_edges, we must clean up
our cached edge resistance data when the invalidate_work_area() is
called on the active workspace, or when the workspace changes.

Make the computation of the edge resistance data lazy so that it
will be recomputed the next time we try to access it.
meta_display_compute_resistance_and_snapping_edges() is made
private to edge-resistance.c

Invaliding the data when active workspace changes also will improve
correctness for edge resistance when the current workspace changes
during a grab operation. (Even with this fix we still don't try to
handle window positions changing during a grab operation; that can't
cause a crash since, unlike screen and monitor edges, the window edges
are freshly allocated, it will just cause slight oddness in that
corner case.)

Root cause tracked down due to much effort by Jon Nettleton.
https://bugzilla.gnome.org/show_bug.cgi?id=608800 (Mutter)
https://bugzilla.gnome.org/show_bug.cgi?id=603632 (Metacity)

Though I haven't tested it, the Metacity reproducer for this should be:

 - In a terminal - type 'sleep 10 && pkill gnome-panel'
 - Start dragging a window

You might have to this a few times, but eventually the strut change as gnome-panel restarts will trigger this crash.

*** Bug 618537 has been marked as a duplicate of this bug. ***

Last dupe we got on https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/889737 is with 2.34 , changing the version number.

I just tried the patch from comment 4 against Ubuntu's metacity 2.34.1.  It did not stop metacity from crashing when I reproduced with the steps from comment 5.  :-/