Fix startoffset for buffer copy

When we have a partial match and no buffer, we copy all of ptr/len and
thus must not touch the startoffset.

We could also copy from startoffset, but that could break lookbehinds,
so don't.

src/tests/c17.vtc

@@ -46,6 +46,12 @@ client c1 -repeat 4 {
 	expect resp.status == 200
 	expect resp.http.all == "a=123,b=43875643543;"
 
+	# simple case - all in one, C-l, 2 matches
+	txreq -body "saldkhaskdhsaks&a=123&sadsadjhsakdh82378e3d&b=43875643543&foobar&a=3&zzz&b=333"
+	rxresp
+	expect resp.status == 200
+	expect resp.http.all == "a=123,b=43875643543;a=3,b=333;"
+
 	txreq -nolen -hdr "Transfer-encoding: chunked"
 	chunked "a="
 	chunked "12"
@@ -61,6 +67,21 @@ client c1 -repeat 4 {
 	expect resp.status == 200
 	expect resp.http.all == "a=123,b=43875643543;a=456,b=782103879213;"
 
+	# 2 matches
+	txreq -nolen -hdr "Transfer-encoding: chunked"
+	chunked "a="
+	chunked "12"
+	chunked "3&sadsadjhsakdh82378e3d&b=43"
+	chunked "875643543&"
+	chunked "saldkhaskdhs"
+	chunked "&a=3"
+	chunked "&zzz&"
+	chunked "b=333"
+	chunkedlen 0
+	rxresp
+	expect resp.status == 200
+	expect resp.http.all == "a=123,b=43875643543;a=3,b=333;"
+
 	txreq -nolen -hdr "Transfer-encoding: chunked"
 	chunked "&&&"
 

src/vmod_re.c

@@ -591,7 +591,6 @@ reip_iter(struct re_iter_priv *reip, unsigned flush,
 		AN(reip->buf);
 		memcpy(reip->buf, ptr, len);
 		reip->len = len;
-		reip->startoffset = ov->ovector[0];
 
 		return (0);
 	}