[Bugs] #4061 sugar-toolkit-gtk3 IMME: Global gesture: can crash Sugar under certain circumstances

[Sugar Labs Bugs]

#4061: Global gesture: can crash Sugar under certain circumstances
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    Reporter:  erikos              |          Owner:  erikos  
        Type:  defect              |         Status:  new     
    Priority:  Immediate           |      Milestone:  0.98    
   Component:  sugar-toolkit-gtk3  |        Version:  0.97.x  
    Severity:  Blocker             |       Keywords:          
Distribution:  OLPC                |   Status_field:  Assigned
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Changes (by dsd):

 * cc: dsd (added)


Comment:

 This is not a crash as such - the process exits with code 1 after the
 final touch is made. No signal is raised.
 Nothing obvious in the logs. I estimated that libX11 might be calling exit
 and indeed this is the case:

 {{{
 Breakpoint 3, _XIOError (warning: Unable to fetch general register.
 warning: Unable to fetch general register.
 dpy=dpy at entry=<unavailable>) at XlibInt.c:1601
 1601    {
 (gdb) bt
 #0  _XIOError (dpy=dpy at entry=<unavailable>) at XlibInt.c:1601
 #1  0xb5d36258 in _XEventsQueued (dpy=<unavailable>, mode=<optimized out>)
     at xcb_io.c:365
 #2  0xb5d36258 in _XEventsQueued (dpy=<unavailable>, mode=<optimized out>)
     at xcb_io.c:365
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 }}}

 Setting a breakpoint on filter_function in sugar-gesture-grabber shows
 that this function is not called on the "crash touch" - the process exits
 before sugar-gesture-grabber is called into.

-- 
Ticket URL: <http://bugs.sugarlabs.org/ticket/4061#comment:2>
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