Created attachment 809232 [details]
backtrace of the segfault, required libraries of falcon and mesa

falkon did crash at exit with segfault. The installation of debug libraries
does reveal a connection to Mesa (this is why I post it, konqi did not give an
address to post so maybe this is not upstream. Feel free to point me upstream
if applicable). 

The backtrace is joint with the attachment. 

Repeatable: well it crashed before, but is irregular, does not happen always.
And this is the first time I get a usable backtrace. 

What the application does: segfaults
What the application should do: should close without segfault.