Is xzgrep broken?

[Jim Long]

xzgrep seems to crap out very quickly when reading a large-ish file
containing compressed ASCII SQL data (834014732 bytes compressed).

# time xzgrep 9314517 /disk1/smbd_share/backup/Daily_backup-20150927-001000.sql.xz  | wc
       0       0       0

real    0m0.005s
user    0m0.011s
sys     0m0.001s

xzcat appears to do better:

# time xzcat /disk1/smbd_share/backup/Daily_backup-20150927-001000.sql.xz  | grep 9314517 | wc
      17  374475 17592746

real    4m0.654s
user    3m45.401s
sys     0m26.678s


# xz -l /disk1/smbd_share/backup/Daily_backup-20150927-001000.sql.xz
Strms  Blocks   Compressed Uncompressed  Ratio  Check   Filename
    1       1    795.4 MiB   8345.1 MiB  0.095  CRC64   /disk1/smbd_share/backup/Daily_backup-20150927-001000.sql.xz


Jim