Merge r4866: Make bytes=-100 work

I have no idea how I overlooked that a "bytes=-100" range was from the
end of the object, but I did.

Fixes #704.

Reported by:    Luc Saillard



git-svn-id: http://www.varnish-cache.org/svn/branches/2.1@5025 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_response.c

@@ -131,7 +131,7 @@ res_do_conds(struct sess *sp)
 static void
 res_dorange(struct sess *sp, const char *r, unsigned *plow, unsigned *phigh)
 {
-	unsigned low, high;
+	unsigned low, high, has_low;
 
 	(void)sp;
 	if (strncmp(r, "bytes=", 6))
@@ -139,10 +139,11 @@ res_dorange(struct sess *sp, const char *r, unsigned *plow, unsigned *phigh)
 	r += 6;
 
 	/* The low end of range */
-	low = 0;
+	has_low = low = 0;
 	if (!vct_isdigit(*r) && *r != '-')
 		return;
 	while (vct_isdigit(*r)) {
+		has_low = 1;
 		low *= 10;
 		low += *r - '0';
 		r++;
@@ -163,6 +164,10 @@ res_dorange(struct sess *sp, const char *r, unsigned *plow, unsigned *phigh)
 			high += *r - '0';
 			r++;
 		}
+		if (!has_low) {
+			low = sp->obj->len - high;
+			high = sp->obj->len - 1;
+		}
 	} else
 		high = sp->obj->len - 1;
 	if (*r != '\0')

bin/varnishtest/tests/c00034.vtc

@@ -59,7 +59,7 @@ client c1 {
 	txreq -hdr "Range: bytes=-9"
 	rxresp
 	expect resp.status == 206
-	expect resp.bodylen == 10
+	expect resp.bodylen == 9
 
 	txreq -hdr "Range: bytes=-"
 	rxresp

bin/varnishtest/tests/r00704.vtc

+# $Id$
+
+test "Range bug"
+
+server s1 {
+	rxreq
+	txresp -bodylen 100
+} -start
+
+varnish v1 -vcl+backend {
+} -start
+
+varnish v1 -cliok "param.set http_range_support on"
+
+
+client c1 {
+	txreq -hdr "Range: bytes=-20"
+	rxresp
+	expect resp.status == 206
+	expect resp.bodylen == 20
+} -run
+