http: Enforce consistently no response body with both 204 and 304 statuses.

Provide AP_STATUS_IS_HEADER_ONLY() helper/macro to check for 204 or 304 and
use it where some special treatment is needed when no body is expected.

Some of those places handled 204 only.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1837056 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 19 insertions, 21 deletions

diff --git a/modules/http/http_filters.c b/modules/http/http_filters.c
index 2887136caf..0610154d68 100644
--- a/modules/http/http_filters.c
+++ b/modules/http/http_filters.c
@@ -1251,7 +1251,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
     }
     else if (ctx->headers_sent) {
         /* Eat body if response must not have one. */
-        if (r->header_only || r->status == HTTP_NO_CONTENT) {
+        if (r->header_only || AP_STATUS_IS_HEADER_ONLY(r->status)) {
             apr_brigade_cleanup(b);
             return APR_SUCCESS;
         }
@@ -1356,12 +1356,15 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
     basic_http_header_check(r, &protocol);
     ap_set_keepalive(r);
 
-    if (r->chunked) {
-        apr_table_mergen(r->headers_out, "Transfer-Encoding", "chunked");
+    if (AP_STATUS_IS_HEADER_ONLY(r->status)) {
+        apr_table_unset(r->headers_out, "Transfer-Encoding");
         apr_table_unset(r->headers_out, "Content-Length");
+        r->content_type = r->content_encoding = NULL;
+        r->content_languages = NULL;
+        r->clength = r->chunked = 0;
     }
-
-    if (r->status == HTTP_NO_CONTENT) {
+    else if (r->chunked) {
+        apr_table_mergen(r->headers_out, "Transfer-Encoding", "chunked");
         apr_table_unset(r->headers_out, "Content-Length");
     }
 
@@ -1440,7 +1443,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f,
     }
     ctx->headers_sent = 1;
 
-    if (r->header_only || r->status == HTTP_NO_CONTENT) {
+    if (r->header_only || AP_STATUS_IS_HEADER_ONLY(r->status)) {
         apr_brigade_cleanup(b);
         goto out;
     }
diff --git a/modules/http/http_protocol.c b/modules/http/http_protocol.c
index 97182dc3d7..928596c29b 100644
--- a/modules/http/http_protocol.c
+++ b/modules/http/http_protocol.c
@@ -254,9 +254,8 @@ AP_DECLARE(int) ap_set_keepalive(request_rec *r)
      */
     if ((r->connection->keepalive != AP_CONN_CLOSE)
         && !r->expecting_100
-        && ((r->status == HTTP_NOT_MODIFIED)
-            || (r->status == HTTP_NO_CONTENT)
-            || r->header_only
+        && (r->header_only
+            || AP_STATUS_IS_HEADER_ONLY(r->status)
             || apr_table_get(r->headers_out, "Content-Length")
             || ap_find_last_token(r->pool,
                                   apr_table_get(r->headers_out,
@@ -1239,26 +1238,22 @@ AP_DECLARE(void) ap_send_error_response(request_rec *r, int recursive_error)
 
     ap_run_insert_error_filter(r);
 
-    /*
-     * It's possible that the Location field might be in r->err_headers_out
-     * instead of r->headers_out; use the latter if possible, else the
-     * former.
-     */
-    if (location == NULL) {
-        location = apr_table_get(r->err_headers_out, "Location");
-    }
     /* We need to special-case the handling of 204 and 304 responses,
      * since they have specific HTTP requirements and do not include a
      * message body.  Note that being assbackwards here is not an option.
      */
-    if (status == HTTP_NOT_MODIFIED) {
+    if (AP_STATUS_IS_HEADER_ONLY(status)) {
         ap_finalize_request_protocol(r);
         return;
     }
 
-    if (status == HTTP_NO_CONTENT) {
-        ap_finalize_request_protocol(r);
-        return;
+    /*
+     * It's possible that the Location field might be in r->err_headers_out
+     * instead of r->headers_out; use the latter if possible, else the
+     * former.
+     */
+    if (location == NULL) {
+        location = apr_table_get(r->err_headers_out, "Location");
     }
 
     if (!r->assbackwards) {