Meaning of proxy_ignore_client_abort

[Jan Prachař]

Hello,

I have proxy module configured with proxy_ignore_client_abort on; but connection to
upstream is still being closed. This is in debug log:

 writev() failed (32: Broken pipe) while sending to client, ...
 http write filter FFFFFFFFFFFFFFFF
 http copy filter: -1 ...
 pipe read upstream: 0
 pipe buf free s:0 t:1 f:0 000055DEBEF95EC0, pos 000055DEBEF95EC0, size: 473 file: 0,
size: 0
 pipe buf free s:0 t:1 f:0 000055DEBEF91EB0, pos 000055DEBEF91EB0, size: 0 file: 0, size:
0
 pipe length: 22594336
 event timer: 23, old: 15583745, new: 15583837
 http upstream downstream error
 finalize http upstream request: -1
 finalize http proxy request
 close http upstream connection: 23

It seems, that check if ignore_client_abort is on, is missing here: 
https://trac.nginx.org/nginx/browser/nginx/src/http/ngx_http_upstream.c#L4223

Or is there any reason why the connection is closed regardless the ignore_client_abort?

Thanks, Jan