whence in PttLock should be SEEK_SET? (or PttLock after lseek should set offset as 0?) about pttbbs

[chhsiao1981]

strangely there are lseek between F_WRLCK / F_UNLCK in the following functions:

record.substitute_record2
record.delete_records
record. delete_record2

Not exactly sure whether it's just that I didn't fully know fnctl / lseek mechanism,
or we do need to change to SEEK_SET in PttLock.

[chhsiao1981]

The reason why record.substitute_record2 works is because lseek is SEEK_SET to same offset before F_WRLCK

The reason why record.delete_records, record.delete_record2 work is because the fd is closed after unlock.
(lock is released and no deadlock.)

[wens]

Based on the usage patterns you listed, which covers about everything, we should probably be using SEEK_SET in PttLock.

[chhsiao1981]

resolved in #101