Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
Linux 2.6.22 amd64. I get a segmentation fault if the target image exists but user does not have permissions to write to it. Using the latest ImageMagick (compiled from sources).
I refined the code a little further. When I compile this on 32bit Linux and run it runs without a crash. On 64 bit Linux I get a segmentation fault. I don't currently have a debug build so the backtrace is not that helpfull.
This seems to be happening everytime the file can not be written (dir does not exist, file permissions and so on).
We can reproduce the problem you reported and have a patch in ImageMagick 6.3.7-10 Beta. The patch will be available sometime tomorrow. Thanks for the bug report.