Description of problem:
dos2unix short-by-1 malloc error causes buffer overrun in rename(), thus
leading to failure

Version-Release number of selected component (if applicable):
3.1-21

How reproducible:
on IA32, at least,
dos2unix /path/that's/multiple/of/4/bytes/file

Steps to Reproduce:
1. as above
2.
3.
  
Actual results:
dos2unix: converting file /path/that's/multiple/of/4/bytes/file  to UNIX format ...
dos2unix: problems renaming '/path/that's/multiple/of/4/bytes/d2utmp8tkzlo^A^O'
to '/path/that's/multiple/of/4/bytes/file'
          output file remains in '/tmp/fsrdata/temp/m1olt00/moebs/d2utmp8tkzlo^A^O'
dos2unix: problems converting file /path/that's/multiple/of/4/bytes/file

in the above, not the presence of the ^A^O (meant to represent the control
characters) at the end of the mkstemp()-derived temp file name. in an strace(1),
the same garbage shows up at the end of the failed rename() syscall, but not
in the mkstemp()'s open() syscall

Expected results:
dos2unix: converting file /path/that's/multiple/of/4/bytes/file  to UNIX format ...

Additional info:
looks like mkstemp() creates the file and stuffs the file name in the too-small
buffer OK but that rename() and even the *printf()'s read beyond the end of the
buffer because the terminal null gets overwritten by something else on the heap