Comment 4 for bug 1065780

I tried different image formats but 8 bit gray, 32 bit color and jpeg make Hugin crash.

After some experimenting it appears that Hugin always crashes on my Mac after these steps:
- Take two small screen shots, ± 80 x 60 pixels.
- Remove hugin Preferences.
- Start Hugin.
- Drag the images into the images pane, fov = 10.
- Save.
- Open Fast Preview window and make it bigger so the images are visible.
- Quit Hugin.
- Change the name of one of the image files.
- Double click the pto file in the Finder.
- Hugin says "image file not found" and crashes.

I tried to do some debugging and put a break in getFileTypeByMagicString. Before "Unable to open file ''." is logged, filename.c_str() is
0xa00aadbc <_ZNSs4_Rep20_S_empty_rep_storageE+12>: ""

#0 0x00fb5b45 in vigra::CodecManager::getFileTypeByMagicString ()
#1 0x00fb5fdf in vigra::CodecManager::getDecoder ()
#2 0x00fb634c in vigra::getDecoder ()
#3 0x00fbfdba in vigra::ImageImportInfo::ImageImportInfo ()
#4 0x01160217 in HuginBase::ImageCache::loadImageSafely ()
#5 0x0116407b in HuginBase::ImageCache::loadSafely ()
#6 0x01168007 in boost::detail::thread_data<boost::_bi::bind_t<void, void (*)(boost::shared_ptr<HuginBase::ImageCache::Request>, boost::shared_ptr<HuginBase::ImageCache::Entry>), boost::_bi::list2<boost::_bi::value<boost::shared_ptr<HuginBase::ImageCache::Request> >, boost::_bi::value<boost::shared_ptr<HuginBase::ImageCache::Entry> > > > >::run ()
#7 0x00df81ac in thread_proxy ()
#8 0x92271259 in _pthread_start ()
#9 0x922710de in thread_start ()