Description of Problem:

Sorry about being a bit vague, but I haven't had time to investigate this yet. 
If/when I do, I will update this bug with better information.  In the mean time,
I have a reliable way of getting composite to crash, so there's definitely a bug.

Version-Release number of selected component (if applicable):

ImageMagick-5.4.7-5

How Reproducible:

always

Steps to Reproduce:
(files attached)
1. composite -compose Difference 1.pgm 2.ppm 3.ppm

Actual Results:

core dump

Expected Results:

This should work.  It works under RedHat 7.3.

Additional Information:
	
Not much yet.  I don't know what it is about these files that causes this
problem.  It may be that any time a .ppm is the output you get this problem, or
it may be related to the fact that there is a mixture of color and gray....
these are guesses.  composite doesn't give any information.  I will try to
compile a debugging version of this and look at it under gdb.

If the last argument is 3.pgm, you don't get a crash.

I'm uploading bzip2'ed versions of these files since they are so large and
compress so well.  Uncompress before running the command, of course.