body_filter_by_lua case some strange behaviors

[9268]

中文讨论：https://groups.google.com/g/openresty/c/kCQM3WcLC-k/m/xPckMVBSBwAJ

by using body_filter_by_lua with ngx.arg[1] uncahange，it return strange truncated response
add chunked_transfer_encoding off ,it return duplicate response line
#file-zcurl-filterandchunkoff-out-L97 && #file-zcurl-filterandchunkoff-out-L142

i test it on latest openresty 1.21.4.1 and Tengine/2.3.2(nginx/1.17.3) , Tengine is all ok

see full conf and debug log here: https://gist.github.com/9268/a9491787efa50201fbc48d82e5de1406

if someone can provide some test case example ，i can write some cases

[zhuizhuhaomeng]

https://github.com/openresty/lua-nginx-module/blob/master/t/082-body-filter.t

These are the original test cases.
You can add some test cases like them.

[9268]

I add 2 cases at https://gist.github.com/9268/a9491787efa50201fbc48d82e5de1406#file-atest-t
pls have a look

[zhuizhuhaomeng]

#2155

There seems no problem in the latest lua-nginx-module.
Plese look at the test case above.

[9268]

sorry,I didn't use this test framework before,and I did't find out my case result in #2155 ,

https://app.travis-ci.com/github/openresty/lua-nginx-module/jobs/596209479#L2947
This shows my case did't run acturally, Can you give me more specific results urls?