nginx with custom modules crashes in gzip crc32()

[artemg]

Thanks for the answer, but its difficult to understand how can that
happen. I even compare output of modified (by my module) response and
unmodified - they are the same, with the only difference that data in
chains is filled in another way. I.e. input data lengths are 100-200-100
bytes (.last - .pos) and after my content rewriting module they can be
0-0-400, or even 0-0-0 chain, and data can be added in next chain. I am
doing buffering to match some patterns. In fact of this I see in error
log:

[alert] 31974#0: *98657 zero size buf in writer t:1 r:1 f:0
0000000001714FE0 0000000001F8D290-0000000001F8D290 0000000000000000 0-0
while sending to client

Is that ok, to have zero size bufs, or I need to modify the chain, not
to pass them forward to other modules?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,216804,216883#msg-216883