If you attempt to concatenate two fonts.scale files by simply appending one
to the other, e.g., if you merge two font directories, mkfontdir won't
detect the resulting corruption (i.e., you've got two count lines in the
file, both of which are wrong, rather than one count line at the top with
the total count in it).  I'll attach a patch which fixes this problem as
well as fixing a security hole -- the code was previously using fscanf into
strings without specifying the size of the strings.