On Mon, Oct 03, 2005 at 11:37:49AM +0200, Tom Parker wrote:
> Sequence of events:
> 1) run "aptitude dist-upgrade"
> 2) get informed that because of conflicts, it can't upgrade
> mozilla-thunderbird, press 'e' at "Accept this solution" prompt
> 3) Enter mozilla-thunderbird package, select later version of
> libpng12-0 (1.2.8rel-4), now lets me upgrade thunderbird to 1.0.7-1
> 4) Press 'g' at "resolve dependancies" screen, and accept the solution
> that's been created
> 5) segfault!
Looks like this assert is tripping:
void decref()
{
assert(refcount > 0);
--refcount;
if(refcount == 0)
cleanup();
}
The actual line number that this was invoked from got optimized away,
but it probably happens when solution_dialog::update() exits and the
smart pointer to 'this' is destroyed.
Could you apply the attached patch (which adds an assert to balance
the other one -- the only widget with a zero reference count is a dead
widget ;-) ) and see if it crashes in a different place? If not, something
highly screwy is happening.
Daniel
Mon Oct 3 19:21:06 PDT 2005 Daniel Burrows <[EMAIL PROTECTED]>
* Disallow (assert against) the creation of strong references to widgets with
a zero reference count.
Since widgets are now created with a reference count of 1, it is now an
invariant that every widget with a zero reference count is dead.
diff -rN -u old-aptitude/src/vscreen/vscreen_widget.h
new-aptitude/src/vscreen/vscreen_widget.h
--- old-aptitude/src/vscreen/vscreen_widget.h 2005-10-03 19:22:32.000000000
-0700
+++ new-aptitude/src/vscreen/vscreen_widget.h 2005-10-03 19:06:23.000000000
-0700
@@ -179,6 +179,8 @@
public:
void incref()
{
+ assert(refcount > 0);
+
++refcount;
}
