merge r3309, r3314, r3315, r3380:

gzip headers related fixes:

*) remove "Content-Encoding: gzip" in 304 response
   sent by ngx_http_gzip_static_module
*) refactor gzip_vary handling
*) test r->header_only last, since it's not actually
   frequent here: 304 and HEAD responses are not set it before the filter

3 files changed, 19 insertions, 3 deletions

diff --git a/src/http/modules/ngx_http_gzip_filter_module.c b/src/http/modules/ngx_http_gzip_filter_module.c
index 62b430b71..2c67a36f1 100644
--- a/src/http/modules/ngx_http_gzip_filter_module.c
+++ b/src/http/modules/ngx_http_gzip_filter_module.c
@@ -246,17 +246,27 @@ ngx_http_gzip_header_filter(ngx_http_request_t *r)
         || (r->headers_out.status != NGX_HTTP_OK
             && r->headers_out.status != NGX_HTTP_FORBIDDEN
             && r->headers_out.status != NGX_HTTP_NOT_FOUND)
-        || r->header_only
         || (r->headers_out.content_encoding
             && r->headers_out.content_encoding->value.len)
         || (r->headers_out.content_length_n != -1
             && r->headers_out.content_length_n < conf->min_length)
         || ngx_http_test_content_type(r, &conf->types) == NULL
-        || ngx_http_gzip_ok(r) != NGX_OK)
+        || r->header_only)
     {
         return ngx_http_next_header_filter(r);
     }
 
+    r->gzip_vary = 1;
+
+    if (!r->gzip_tested) {
+        if (ngx_http_gzip_ok(r) != NGX_OK) {
+            return ngx_http_next_header_filter(r);
+        }
+
+    } else if (!r->gzip_ok) {
+        return ngx_http_next_header_filter(r);
+    }
+
     ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_gzip_ctx_t));
     if (ctx == NULL) {
         return NGX_ERROR;
diff --git a/src/http/modules/ngx_http_gzip_static_module.c b/src/http/modules/ngx_http_gzip_static_module.c
index 45ab6aaa2..29874a33a 100644
--- a/src/http/modules/ngx_http_gzip_static_module.c
+++ b/src/http/modules/ngx_http_gzip_static_module.c
@@ -144,7 +144,6 @@ ngx_http_gzip_static_handler(ngx_http_request_t *r)
         case NGX_ENOTDIR:
         case NGX_ENAMETOOLONG:
 
-            r->gzip = 0;
             return NGX_DECLINED;
 
         case NGX_EACCES:
@@ -164,6 +163,8 @@ ngx_http_gzip_static_handler(ngx_http_request_t *r)
         return NGX_DECLINED;
     }
 
+    r->gzip_vary = 1;
+
     if (rc != NGX_OK) {
         return NGX_DECLINED;
     }
diff --git a/src/http/modules/ngx_http_not_modified_filter_module.c b/src/http/modules/ngx_http_not_modified_filter_module.c
index 5312b3a22..705815740 100644
--- a/src/http/modules/ngx_http_not_modified_filter_module.c
+++ b/src/http/modules/ngx_http_not_modified_filter_module.c
@@ -88,6 +88,11 @@ ngx_http_not_modified_header_filter(ngx_http_request_t *r)
     ngx_http_clear_content_length(r);
     ngx_http_clear_accept_ranges(r);
 
+    if (r->headers_out.content_encoding) {
+        r->headers_out.content_encoding->hash = 0;
+        r->headers_out.content_encoding = NULL;
+    }
+
     return ngx_http_next_header_filter(r);
 }