Comment 3 for bug 1368492

Better stack trace with debug symbols installed:
Core was generated by `./gallery-app'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0xb5b2201c in std::string::assign(std::string const&) ()
   from /usr/lib/arm-linux-gnueabihf/libstdc++.so.6
(gdb) bt
#0 0xb5b2201c in std::string::assign(std::string const&) ()
   from /usr/lib/arm-linux-gnueabihf/libstdc++.so.6
#1 0xacebe712 in operator= (__str=..., this=0xa68cc6fc)
    at /usr/include/c++/4.9/bits/basic_string.h:555
#2 ThumbnailCachePrivate::get_cache_file_name (this=0x0, abs_original=...,
    desired=desired@entry=TN_SIZE_LARGE)
    at /build/buildd/thumbnailer-1.2+14.10.20140814/src/thumbnailcache.cpp:246
#3 0xacebec62 in ThumbnailCache::get_if_exists (this=0x7641d4, abs_path=...,
    desired_size=desired_size@entry=TN_SIZE_LARGE)
    at /build/buildd/thumbnailer-1.2+14.10.20140814/src/thumbnailcache.cpp:264
#4 0xacebff34 in Thumbnailer::get_thumbnail (this=0x490db8, filename=...,
    desired_size=TN_SIZE_LARGE, policy=policy@entry=TN_LOCAL)
    at /build/buildd/thumbnailer-1.2+14.10.20140814/src/thumbnailer.cpp:197
#5 0xacec00ae in Thumbnailer::get_thumbnail (this=<optimized out>,
    filename=..., desired_size=<optimized out>)
    at /build/buildd/thumbnailer-1.2+14.10.20140814/src/thumbnailer.cpp:201
#6 0xacf7b70e in ThumbnailGenerator::requestImage(QString const&, QSize*, QSize const&) ()
   from /usr/lib/arm-linux-gnueabihf/qt5/qml/Ubuntu/Components/libUbuntuComponents.so
#7 0xb640acfa in ?? () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)