BUG/MINOR: mux-fcgi: Handle empty STDERR record
As mentionned in the FastCGI specification, FCGI "streams" are series of
non-empty stream records (length != 0), followed by an empty one. It is properly
handled for FCGI_STDOUT records, but not for FCGI_STDERR ones. If an empty
FCGI_STDERR record is received, the connection is blocked waiting for data which
will never come.
To fix the bug, when an empty FCGI_STDERR record is received, we drop it, eating
the padding if any.
This patch should fix the issue #743. It must be backported as far as 2.1.
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index 58d4923..d1094d9 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -2355,7 +2355,7 @@
dbuf = &fconn->dbuf;
/* Only padding remains */
- if (fconn->state == FCGI_CS_RECORD_P)
+ if (fconn->state == FCGI_CS_RECORD_P || !fconn->drl)
goto end_transfer;
if (b_data(dbuf) < (fconn->drl + fconn->drp) &&