On pass (from vcl_recv) we did not remove the backends Content-Length

header before adding our own.

We can not do this with the fetch filtering, because pass might send
HEAD requests to the backend.

XXX: It's arguable that the filtering stuff might be better done
inline than with a table.

Fixes: #801



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5461 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_fetch.c

@@ -552,9 +552,11 @@ FetchBody(struct sess *sp)
 		assert(uu == sp->obj->len);
 	}
 
-	if (mklen > 0)
+	if (mklen > 0) {
+		http_Unset(sp->obj->http, H_Content_Length);
 		http_PrintfHeader(sp->wrk, sp->fd, sp->obj->http,
 		    "Content-Length: %u", sp->obj->len);
+	}
 
 	if (http_HdrIs(hp, H_Connection, "close"))
 		cls = 1;

bin/varnishtest/tests/r00801.vtc

+# $Id$
+
+test "Regression test for duplicate content-length in pass"
+
+server s1 {
+	rxreq
+	txresp \
+		-hdr "Date: Mon, 25 Oct 2010 06:34:06 GMT" \
+		-hdr "Content-length: 10xx" \
+		-nolen -bodylen 10
+} -start
+
+
+varnish v1 -vcl+backend {
+	sub vcl_recv { return (pass); }
+} -start
+
+client c1 {
+	txreq 
+	rxresp
+	expect resp.http.content-length == "10"
+} -run
+
+