NAME
    OpenFromLock -- Opens a file you have a lock on (V36)

SYNOPSIS
    fh = OpenFromLock(lock)
    D0                 D1

    BPTR OpenFromLock(BPTR)

FUNCTION
    Given a lock, this routine performs an open on that lock.  If the open
    succeeds, the lock is (effectively) relinquished, and should not be
    UnLock()ed or used.  If the open fails, the lock is still usable.
    The lock associated with the file internally is of the same access
    mode as the lock you gave up - shared is similar to MODE_OLDFILE,
    exclusive is similar to MODE_NEWFILE.

INPUTS
    lock - Lock on object to be opened.

RESULT
    fh   - Newly opened file handle or NULL for failure

BUGS
    In the original V36 autodocs, this was shown (incorrectly) as
    taking a Mode parameter as well.  The prototypes and pragmas were
    also wrong.

SEE ALSO
    open(), close(), lock(), unlock()