Entity tags: clear on entity changes.

src/http/modules/ngx_http_addition_filter_module.c

@@ -121,6 +121,7 @@ ngx_http_addition_header_filter(ngx_http_request_t *r)
 
     ngx_http_clear_content_length(r);
     ngx_http_clear_accept_ranges(r);
+    ngx_http_clear_etag(r);
 
     return ngx_http_next_header_filter(r);
 }

src/http/modules/ngx_http_gzip_filter_module.c

@@ -306,6 +306,7 @@ ngx_http_gzip_header_filter(ngx_http_request_t *r)
 
     ngx_http_clear_content_length(r);
     ngx_http_clear_accept_ranges(r);
+    ngx_http_clear_etag(r);
 
     return ngx_http_next_header_filter(r);
 }

src/http/modules/ngx_http_ssi_filter_module.c

@@ -361,6 +361,7 @@ ngx_http_ssi_header_filter(ngx_http_request_t *r)
         ngx_http_clear_content_length(r);
         ngx_http_clear_last_modified(r);
         ngx_http_clear_accept_ranges(r);
+        ngx_http_clear_etag(r);
     }
 
     return ngx_http_next_header_filter(r);

src/http/modules/ngx_http_sub_filter_module.c

@@ -168,6 +168,7 @@ ngx_http_sub_header_filter(ngx_http_request_t *r)
     if (r == r->main) {
         ngx_http_clear_content_length(r);
         ngx_http_clear_last_modified(r);
+        ngx_http_clear_etag(r);
     }
 
     return ngx_http_next_header_filter(r);

src/http/modules/ngx_http_xslt_filter_module.c

@@ -328,6 +328,7 @@ ngx_http_xslt_send(ngx_http_request_t *r, ngx_http_xslt_filter_ctx_t *ctx,
         }
 
         ngx_http_clear_last_modified(r);
+        ngx_http_clear_etag(r);
     }
 
     rc = ngx_http_next_header_filter(r);

src/http/ngx_http_core_module.h

@@ -555,5 +555,12 @@ extern ngx_str_t  ngx_http_core_get_method;
         r->headers_out.location = NULL;                                       \
     }
 
+#define ngx_http_clear_etag(r)                                                \
+                                                                              \
+    if (r->headers_out.etag) {                                                \
+        r->headers_out.etag->hash = 0;                                        \
+        r->headers_out.etag = NULL;                                           \
+    }
+
 
 #endif /* _NGX_HTTP_CORE_H_INCLUDED_ */

src/http/ngx_http_special_response.c

@@ -656,6 +656,7 @@ ngx_http_send_special_response(ngx_http_request_t *r,
 
     ngx_http_clear_accept_ranges(r);
     ngx_http_clear_last_modified(r);
+    ngx_http_clear_etag(r);
 
     rc = ngx_http_send_header(r);
 
@@ -754,6 +755,7 @@ ngx_http_send_refresh(ngx_http_request_t *r)
 
     ngx_http_clear_accept_ranges(r);
     ngx_http_clear_last_modified(r);
+    ngx_http_clear_etag(r);
 
     rc = ngx_http_send_header(r);