Move bereq.http to req->ws for vcl_pipe

Also make sure we didn't overflow before entering vcl_pipe. This would
mean we have lost important connection headers.

bin/varnishd/cache/cache_req_fsm.c

@@ -745,7 +745,7 @@ cnt_pipe(struct worker *wrk, struct req *req)
 	bo->sp = req->sp;
 	SES_Ref(bo->sp);
 
-	HTTP_Setup(bo->bereq, bo->ws, bo->vsl, SLT_BereqMethod);
+	HTTP_Setup(bo->bereq, req->ws, bo->vsl, SLT_BereqMethod);
 	http_FilterReq(bo->bereq, req->http, 0);	// XXX: 0 ?
 	http_PrintfHeader(bo->bereq, "X-Varnish: %u", VXID(req->vsl->wid));
 	http_ForceHeader(bo->bereq, H_Connection, "close");
@@ -756,7 +756,10 @@ cnt_pipe(struct worker *wrk, struct req *req)
 	}
 
 	bo->wrk = wrk;
-	VCL_pipe_method(req->vcl, wrk, req, bo, NULL);
+	if (WS_Overflowed(req->ws))
+		wrk->handling = VCL_RET_FAIL;
+	else
+		VCL_pipe_method(req->vcl, wrk, req, bo, NULL);
 
 	switch (wrk->handling) {
 	case VCL_RET_SYNTH:

bin/varnishtest/tests/r03329.vtc

@@ -3,11 +3,20 @@ varnishtest "Lost reason from pipe to synth"
 server s1 {} -start
 
 varnish v1 -vcl+backend {
+	import vtc;
 	sub vcl_recv {
+		if (req.http.workspace) {
+			vtc.workspace_alloc(client, -10);
+		}
 		return (pipe);
 	}
 	sub vcl_pipe {
-		return (synth(505, req.http.foo + "/bar"));
+		if (req.http.foo) {
+			return (synth(505, req.http.foo + "/bar"));
+		} else {
+			set bereq.http.baz = "baz";
+			return (synth(505, bereq.http.baz));
+		}
 	}
 } -start
 
@@ -15,4 +24,12 @@ client c1 {
 	txreq -hdr "foo: foo"
 	rxresp
 	expect resp.reason == "foo/bar"
+
+	txreq
+	rxresp
+	expect resp.reason == "baz"
+
+	txreq -hdr "workspace: true"
+	rxresp
+	expect resp.status == 503
 } -run