Fixed "zero size buf" alerts with subrequests.

Since 4611:2b6cb7528409 responses from the gzip static, flv, and mp4 modules
can be used with subrequests, though empty files were not properly handled.
Empty gzipped, flv, and mp4 files thus resulted in "zero size buf in output"
alerts.  While valid corresponding files are not expected to be empty, such
files shouldn't result in alerts.

Fix is to set b->sync on such empty subrequest responses, similarly to what
ngx_http_send_special() does.

Additionally, the static module, the ngx_http_send_response() function, and
file cache are modified to do the same instead of not sending the response
body at all in such cases, since not sending the response body at all is
believed to be at least questionable, and might break various filters
which do not expect such behaviour.

diff --git a/src/http/modules/ngx_http_flv_module.c b/src/http/modules/ngx_http_flv_module.c
index a7ee53cbb58b780512742ee9597e4ee445463458..ef2bff433f808130ef910799b104069bbfb72922 100644 (file)
--- a/src/http/modules/ngx_http_flv_module.c
+++ b/src/http/modules/ngx_http_flv_module.c
@@ -235,6 +235,7 @@ ngx_http_flv_handler(ngx_http_request_t *r)
     b->in_file = b->file_last ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->in_file) ? 0 : 1;
 
     b->file->fd = of.fd;
     b->file->name = path;

diff --git a/src/http/modules/ngx_http_gzip_static_module.c b/src/http/modules/ngx_http_gzip_static_module.c
index 0ab14636e6c4359ca523a8ba2f6d5a99b570740a..91b38d17bee703bc1e36c9513a891953912c3273 100644 (file)
--- a/src/http/modules/ngx_http_gzip_static_module.c
+++ b/src/http/modules/ngx_http_gzip_static_module.c
@@ -273,6 +273,7 @@ ngx_http_gzip_static_handler(ngx_http_request_t *r)
     b->in_file = b->file_last ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->in_file) ? 0 : 1;
 
     b->file->fd = of.fd;
     b->file->name = path;

diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index 75a7315f9879dc97b125b310a98d79aed062f60d..03175dea214b56a20e40b342ca82131926b555fa 100644 (file)
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -714,6 +714,7 @@ ngx_http_mp4_handler(ngx_http_request_t *r)
     b->in_file = b->file_last ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->in_file) ? 0 : 1;
 
     b->file->fd = of.fd;
     b->file->name = path;

diff --git a/src/http/modules/ngx_http_static_module.c b/src/http/modules/ngx_http_static_module.c
index 3e65edfdb1d3f35e1adfd0b379f89787fa7920c4..8b0bb1478db5bc155b9777f8bd5810ddf72a97a8 100644 (file)
--- a/src/http/modules/ngx_http_static_module.c
+++ b/src/http/modules/ngx_http_static_module.c
@@ -238,10 +238,6 @@ ngx_http_static_handler(ngx_http_request_t *r)
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    if (r != r->main && of.size == 0) {
-        return ngx_http_send_header(r);
-    }
-
     r->allow_ranges = 1;
 
     /* we need to allocate all before the header would be sent */
@@ -268,6 +264,7 @@ ngx_http_static_handler(ngx_http_request_t *r)
     b->in_file = b->file_last ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->in_file) ? 0 : 1;
 
     b->file->fd = of.fd;
     b->file->name = path;

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 6b1cb4fa4b9ea120f17c7b727cea2c1a6f8cb3b1..2140e06279c3826383217df97c70875053b847f1 100644 (file)
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -1803,10 +1803,6 @@ ngx_http_send_response(ngx_http_request_t *r, ngx_uint_t status,
         }
     }
 
-    if (r != r->main && val.len == 0) {
-        return ngx_http_send_header(r);
-    }
-
     b = ngx_calloc_buf(r->pool);
     if (b == NULL) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
@@ -1817,6 +1813,7 @@ ngx_http_send_response(ngx_http_request_t *r, ngx_uint_t status,
     b->memory = val.len ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->memory) ? 0 : 1;
 
     out.buf = b;
     out.next = NULL;

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index 8db24f10379d5c734af2cf0c31fd14041f828237..aa5fd1917259b650e0172be1b593c53357d73e4f 100644 (file)
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -1575,10 +1575,6 @@ ngx_http_cache_send(ngx_http_request_t *r)
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http file cache send: %s", c->file.name.data);
 
-    if (r != r->main && c->length - c->body_start == 0) {
-        return ngx_http_send_header(r);
-    }
-
     /* we need to allocate all before the header would be sent */
 
     b = ngx_calloc_buf(r->pool);
@@ -1603,6 +1599,7 @@ ngx_http_cache_send(ngx_http_request_t *r)
     b->in_file = (c->length - c->body_start) ? 1 : 0;
     b->last_buf = (r == r->main) ? 1 : 0;
     b->last_in_chain = 1;
+    b->sync = (b->last_buf || b->in_file) ? 0 : 1;
 
     b->file->fd = c->file.fd;
     b->file->name = c->file.name;