From aafa2004d7bb9b3a9cb9970d793a136de85517c3 Mon Sep 17 00:00:00 2001
From: Igor Sysoev <igor@sysoev.ru>
Date: Wed, 17 Jan 2007 16:10:40 +0000
Subject: [PATCH] fix FastCGI "zero size buf" alert, r841 did not fix it

---
 src/event/ngx_event_pipe.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/event/ngx_event_pipe.c b/src/event/ngx_event_pipe.c
index 0239bd105..0809f9bae 100644
--- a/src/event/ngx_event_pipe.c
+++ b/src/event/ngx_event_pipe.c
@@ -420,7 +420,7 @@ static ngx_int_t
 ngx_event_pipe_write_to_downstream(ngx_event_pipe_t *p)
 {
     size_t             bsize;
-    ngx_uint_t         flush;
+    ngx_uint_t         flush, prev_last_shadow;
     ngx_chain_t       *out, **ll, *cl;
     ngx_connection_t  *downstream;
 
@@ -511,6 +511,7 @@ ngx_event_pipe_write_to_downstream(ngx_event_pipe_t *p)
         out = NULL;
         ll = NULL;
         flush = 0;
+        prev_last_shadow = 1;
 
         for ( ;; ) {
             if (p->out) {
@@ -520,10 +521,16 @@ ngx_event_pipe_write_to_downstream(ngx_event_pipe_t *p)
                     && cl->buf->last_shadow
                     && bsize + cl->buf->last - cl->buf->pos > p->busy_size)
                 {
+                    if (!prev_last_shadow) {
+                        p->in = p->in->next;
+                    }
+
                     flush = 1;
                     break;
                 }
 
+                prev_last_shadow = cl->buf->last_shadow;
+
                 p->out = p->out->next;
 
                 ngx_event_pipe_free_shadow_raw_buf(&p->free_raw_bufs, cl->buf);
@@ -541,10 +548,16 @@ ngx_event_pipe_write_to_downstream(ngx_event_pipe_t *p)
                     && cl->buf->last_shadow
                     && bsize + cl->buf->last - cl->buf->pos > p->busy_size)
                 {
+                    if (!prev_last_shadow) {
+                        p->in = p->in->next;
+                    }
+
                     flush = 1;
                     break;
                 }
 
+                prev_last_shadow = cl->buf->last_shadow;
+
                 p->in = p->in->next;
 
             } else {