This is another case where the Windows behavior may be incorrect. It's also a corner case scenario so isn't high priority for a fix. When attempting a 0-byte read on a range of a file that is locked, Windows returns STATUS_OK to the read while Samba4 server returns STATUS_FILE_LOCK_CONFLICT. This is exercised by the RAW-LOCK-ZEROBYTEREAD and SMB2-LOCK-ZEROBYTEREAD smbtorture4 tests. These tests are currently listed in source4/selftest/knownfail
Reassign file server related bugs up to tridge.