The direction specified by the offset was essentially reversed when calling lseek with whence==2 (seek to offset from end of file). Therefore, specifying a negative offset with whence==2 would fail, rather than seeking before the end of the file as it should.
(The ORCA/C manual is not totally clear about this behavior, but the new behavior is consistent with the POSIX spec and all other implementations I'm aware of, including traditional Unix and APW C. Note that Unix/POSIX allows seeking beyond the end of the file, but GS/OS does not.)
There are also improvements to error handling, so lseek consistently reports EINVAL for invalid offsets.
Stephen Heumann
Kelvin Sherlock
mikew50