Segmentation fault in QXcbScreen::mapFromNative in 0.12.0 executable #7582
Description
Reported on IRC by fakesatoshi. This crash seems to happen randomly while clicking:
[16419.562321] bitcoin-qt[1892]: segfault at 0 ip 00007fa82a53da1c sp 00007fffc4391810 error 4 in bitcoin-qt[7fa829fcf000+1e2e000]
[17045.871471] bitcoin-qt[2061]: segfault at 0 ip 00007f3b4b694a1c sp 00007ffc0739bd50 error 4 in bitcoin-qt[7f3b4b126000+1e2e000]
[20753.833830] bitcoin-qt[2891]: segfault at 0 ip 00007f7bfbff1a1c sp 00007ffd5ffe2880 error 4 in bitcoin-qt[7f7bfba83000+1e2e000]
This is offset 0x56ea1c in the 64-bit bitcoin-qt executable. Addr2line (on a non-stripped version of the executable) gives us:
addr2line -aCf -e bitcoin-0.12.0/bin/bitcoin-qt 0x56ea1c
0x000000000056ea1c
QXcbScreen::mapFromNative(QPoint const&) const
:?
Operating system: Debian Jessie
Linux vbox 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt20-1+deb8u3 (2016-01-17) x86_64 GNU/Linux
No full traceback is available as it doesn't seem to be reproducible in gdb.
From at the assembly around the crash eip it looks like the first argument, the implicit this argument is 0.
000000000056ea10 <_ZNK10QXcbScreen13mapFromNativeERK6QPoint>:
56ea10: 55 push %rbp
56ea11: 48 89 f5 mov %rsi,%rbp
56ea14: 53 push %rbx
56ea15: 48 89 fb mov %rdi,%rbx
56ea18: 48 83 ec 08 sub $0x8,%rsp
56ea1c: 48 8b 07 mov (%rdi),%rax
What could cause an XcbScreen to be 0? @theuni any idea?