# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1427133418 -10800
# Node ID 6ab301ddf469cb0a51cca7cf839e6117789af499
# Parent  b8926ba4d087f2daa3d0ba2681346d49be40d5dc
Output chain: zero size buf alerts in ngx_chain_writer().

Now we log a "zero size buf in chain writer" alert if we encounter a zero
sized buffer in ngx_chain_writer(), and skip the buffer.

diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -663,7 +663,23 @@ ngx_chain_writer(void *data, ngx_chain_t
 
 #if 1
         if (ngx_buf_size(in->buf) == 0 && !ngx_buf_special(in->buf)) {
+
+            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
+                          "zero size buf in chain writer "
+                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+                          in->buf->temporary,
+                          in->buf->recycled,
+                          in->buf->in_file,
+                          in->buf->start,
+                          in->buf->pos,
+                          in->buf->last,
+                          in->buf->file,
+                          in->buf->file_pos,
+                          in->buf->file_last);
+
             ngx_debug_point();
+
+            continue;
         }
 #endif
 
@@ -691,9 +707,24 @@ ngx_chain_writer(void *data, ngx_chain_t
 
 #if 1
         if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) {
+
+            ngx_log_error(NGX_LOG_ALERT, ctx->pool->log, 0,
+                          "zero size buf in chain writer "
+                          "t:%d r:%d f:%d %p %p-%p %p %O-%O",
+                          cl->buf->temporary,
+                          cl->buf->recycled,
+                          cl->buf->in_file,
+                          cl->buf->start,
+                          cl->buf->pos,
+                          cl->buf->last,
+                          cl->buf->file,
+                          cl->buf->file_pos,
+                          cl->buf->file_last);
+
             ngx_debug_point();
+
+            continue;
         }
-
 #endif
 
         size += ngx_buf_size(cl->buf);