Re: HEAD response's Content-Length stripped when zero

[Yann Ylavic]

(sorry for the patches spam / confused proposal)

On Wed, Apr 29, 2015 at 6:07 PM, Yann Ylavic <ylavic....@gmail.com> wrote:
> We could also avoid the note by setting r->clength = -1 instead in
> ap_content_length_filter().

Another candidate could be r->sent_bodyct = 1, eg:

Index: server/protocol.c
===================================================================
--- server/protocol.c    (revision 1676716)
+++ server/protocol.c    (working copy)
@@ -1533,7 +1533,7 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_content_le
      * We can only set a C-L in the response header if we haven't already
      * sent any buckets on to the next output filter for this request.
      */
-    if (ctx->data_sent == 0 && eos &&
+    if (ctx->data_sent == 0 && eos) {
         /* don't whack the C-L if it has already been set for a HEAD
          * by something like proxy.  the brigade only has an EOS bucket
          * in this case, making r->bytes_sent zero.
@@ -1544,9 +1544,16 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_content_le
          * such filters update or remove the C-L header, and just use it
          * if present.
          */
-        !(r->header_only && r->bytes_sent == 0 &&
-            apr_table_get(r->headers_out, "Content-Length"))) {
-        ap_set_content_length(r, r->bytes_sent);
+        if (r->header_only && r->bytes_sent == 0 &&
+                apr_table_get(r->headers_out, "Content-Length")) {
+            /* Tell ap_http_header_filter() we don't want the C-L to
+             * be stripped (ie. the original no-body is sent now).
+             */
+            r->sent_bodyct = 1;
+        }
+        else {
+            ap_set_content_length(r, r->bytes_sent);
+        }
     }

     ctx->data_sent = 1;
Index: modules/http/http_filters.c
===================================================================
--- modules/http/http_filters.c    (revision 1676716)
+++ modules/http/http_filters.c    (working copy)
@@ -1292,9 +1292,9 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_http_heade
      * The default (unset) behavior is to squelch the C-L in this case.
      */
     if (r->header_only
-        && (clheader = apr_table_get(r->headers_out, "Content-Length"))
-        && !strcmp(clheader, "0")
-        && conf->http_cl_head_zero != AP_HTTP_CL_HEAD_ZERO_ENABLE) {
+            && !r->sent_bodyct
+            && (clheader = apr_table_get(r->headers_out, "Content-Length"))
+            && !strcmp(clheader, "0")) {
         apr_table_unset(r->headers_out, "Content-Length");
     }

--