git-grep Bus Error

The --color display code in git-grep is giving me a bus error in  
show_line at line 492:

                        printf("%.*s%s%.*s%s",
                               match.rm_so, bol,
                               opt->color_match,
                               match.rm_eo - match.rm_so, bol +  
match.rm_so,
                               GIT_COLOR_RESET);

The first problem is that %.*s does not appear to do on OS X what the  
author thinks it does.  A precision of 0 for %s is listed in "man  
printf" as printing the entire string.

To fix that, I changed it to the following:

			if( match.rm_so > 0 )
				printf( "%.*s", match.rm_so, bol );
			if( match.rm_eo > match.rm_so )
				printf("%s%.*s%s",
					   opt->color_match,
					   match.rm_eo - match.rm_so, bol + match.rm_so,
					   GIT_COLOR_RESET);

This code does not fail, but instead gives lines like the following  
(showing the raw color codes):

.gitignore:\033[31m\033[1m(nugit

GIT_COLOR_RESET is apparently being ignored, and I don't know why.

Adding a line to check the values of rm_so, rm_eo, and the difference  
between the two gives:

			printf( "%d %d %d",
				  match.rm_so, match.rm_eo,
				  match.rm_eo - match.rm_so );

.gitignore:0 0 3\033[31m\033[1m(nugit
.mailmap:23 0 26(null)\033[31m\033[1m(nugit-shortlog to fix a few  
botched name translations-shortlog to fix a few botched name  
translations

And now I'm baffled.  Apparently my computer thinks 0 - 0 == 3 and 0 -  
23 == 26.

Can I get some help?

~~ Brian