Use VRT_fail in case silly HTTP status numbers are set, and test that.

bin/varnishd/cache/cache_vrt_var.c

@@ -97,17 +97,14 @@ VRT_l_##obj##_status(VRT_CTX, long num)					\
 									\
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);				\
 	CHECK_OBJ_NOTNULL(ctx->http_##obj, HTTP_MAGIC);			\
-	if (num > 65535) {						\
-		VSLb(ctx->vsl, SLT_VCL_Error,				\
-		    "%s.status > 65535", #obj);				\
-		WS_MarkOverflow(ctx->http_##obj->ws);			\
-	} else if ((num % 1000) < 100) {				\
-		VSLb(ctx->vsl, SLT_VCL_Error,				\
-		    "illegal %s.status (..0##)", #obj);			\
-		WS_MarkOverflow(ctx->http_##obj->ws);			\
-	} else {							\
+	if (num < 0)							\
+		VRT_fail(ctx, "%s.status (%ld) is negative", #obj, num); \
+	else if (num > 65535)						\
+		VRT_fail(ctx, "%s.status (%ld) > 65535", #obj, num);	\
+	else if ((num % 1000) < 100)					\
+		VRT_fail(ctx, "illegal %s.status (%ld) (..0##)", #obj, num); \
+	else								\
 		http_SetStatus(ctx->http_##obj, (uint16_t)num);		\
-	}								\
 }
 
 #define VRT_STATUS_R(obj)						\

bin/varnishtest/tests/v00050.vtc

@@ -91,6 +91,15 @@ varnish v1 -vcl+backend {
 		    return (synth(400));
 		}
 	    }
+	    if (req.http.huge == "yes") {
+		set resp.status = 65536;
+	    }
+	    if (req.http.small == "yes") {
+		set resp.status = 99;
+	    }
+	    if (req.http.negative == "yes") {
+		set resp.status = -200;
+	    }
 	}
 
 	sub vcl_recv {
@@ -100,6 +109,9 @@ varnish v1 -vcl+backend {
 	}
 
 	sub vcl_synth {
+	    if (resp.reason == "VCL failed") {
+		return (deliver);
+	    }
 	    std.log("synth " + resp.status + " " + resp.reason);
 	    if (resp.status != 22301) {
 		set resp.status = 501;
@@ -148,10 +160,35 @@ client c1 {
 	rxresp
 	expect resp.status == 302
 	expect resp.reason == "Wrong Postcode"
-}
+} -run
+
+logexpect l1 -v v1 {
+	expect * * VCL_Error "illegal resp.status .99. ...0##."
+	expect * * VCL_Error "resp.status .65536. > 65535"
+	expect * * VCL_Error "resp.status .-200. is negative"
+} -start
 
-client c1 -run
+client c1 {
+	txreq -url "/a" -hdr "Small: yes"
+	rxresp
+	expect resp.status == 503
+	expect resp.reason == "VCL failed"
+
+	expect_close
+} -run
+
+client c1 {
+	txreq -url "/a" -hdr "Huge: yes"
+	rxresp
+	expect resp.status == 503
+	expect resp.reason == "VCL failed"
+} -run
 
-server s1 -wait
+client c1 {
+	txreq -url "/a" -hdr "Negative: yes"
+	rxresp
+	expect resp.status == 503
+	expect resp.reason == "VCL failed"
+} -run
 
-varnish v1 -stop
+logexpect l1 -wait