prior to r195693, since historical behaviour of mmap(2) was to silently
ignore length-zero mmap requests; but mmap now returns EINVAL, which caused
look(1) to emit an error message and fail.
Among other things, this makes `freebsd-update fetch` on a newly installed
8.0-BETA3 system print bogus warning messages.
MFC after: 3 days
Add some constness to avoid some warnings.
Remove use register keyword.
Deal with missing/unneeded extern/prototypes.
Some minor type changes/casts to avoid warnings.
Reviewed by: md5
- Use MAP_FAILED instead of the constant -1 to indicate
failure (required by POSIX).
- Removed flag arguments of '0' (required by POSIX).
- Fixed code which expected an error return of 0.
- Fixed code which thought any address with the high bit set
was an error.
- Check for failure where no checks were present.
Discussed with: bde
