suspect found for openGL preview crash

[kfj]

Hi group!

I've recently been annoyed by the openGL preview crashing when I had
previously disabled the panosphere view and then restarted hugin.
Hugin would crash a few times, but sometimes after some blind trying
this and that would come round again. So I launched hugin under gdb
from a console window and got a hint at where the problem occurs:

Program received signal SIGSEGV, Segmentation fault.
PreviewIdentifyTool::UpdateWithNewImageSet (this=0x0,
new_image_set=...)
at /home/kfj/src/hugin/hugin_clean.hg/src/hugin1/hugin/
PreviewIdentifyTool.cpp:567
567 std::vector<unsigned int>
difference(new_image_set.size());

this = 0x0 definitely looks bad, but I also found that of
new_image_set.size() was zero. After a bit of trial and error I ended
up simply putting the whole body of code inside the method in question
into a conditional:

void PreviewIdentifyTool::UpdateWithNewImageSet(std::set<unsigned int>
new_image_set)
{
if ( new_image_set.size() )
{
...
}
}

now the error was gone. I might just have been lucky, but since then I
could not get the bug to occur. Since I haven't really got a clue what
the code does, I'm not sure if my quick shot will be a solution, but
maybe it's a start :)

I also put a copy of this message into the bug tracker.

Kay