add tests for the sub() method to vcl_regex.vtc

src/tests/vcl_regex.vtc

 # looks like -*- vcl -*-
 
-varnishtest "re2.backref not affected by standard VCL regex code"
+varnishtest "backrefs not affected by standard VCL regex code"
 
 varnish v1 -vcl+backend {
 	import re2 from "${vmod_topbuild}/src/.libs/libvmod_re2.so";
@@ -23,6 +23,8 @@ varnish v1 -vcl+backend {
 		if (resp.http.foo ~ "bar(baz)") {
 			set resp.http.tilde0 = barbaz.backref(0, "tilde0");
 			set resp.http.tilde1 = barbaz.backref(1, "tilde1");
+			set resp.http.tildesub =
+				barbaz.sub(resp.http.foo, "\0\1", "tildesub");
 		} else {
 			set resp.status = 999;
 		}
@@ -30,6 +32,8 @@ varnish v1 -vcl+backend {
 		if (resp.http.foo !~ "bar(quux)") {
 			set resp.http.neg0 = barbaz.backref(0, "neg0");
 			set resp.http.neg1 = barbaz.backref(1, "neg1");
+			set resp.http.negsub =
+				barbaz.sub(resp.http.foo, "\0\1", "negsub");
 		} else {
 			set resp.status = 999;
 		}
@@ -38,11 +42,15 @@ varnish v1 -vcl+backend {
 		    = regsub(resp.http.foo, "bar(baz)", "\1");
 		set resp.http.regsub0 = barbaz.backref(0, "regsub0");
 		set resp.http.regsub1 = barbaz.backref(1, "regsub1");
+		set resp.http.regsubsub = barbaz.sub(resp.http.foo, "\0\1",
+                                                     "regsubsub");
 
 		set resp.http.regsuball
 		    = regsuball(resp.http.foo, "(.)", "x");
 		set resp.http.regsuball0 = barbaz.backref(0, "regsuball0");
 		set resp.http.regsuball1 = barbaz.backref(1, "regsuball1");
+		set resp.http.regsuballsub = barbaz.sub(resp.http.foo, "\0\1",
+                                                        "regsuballsub");
 	}
 
 } -start
@@ -53,14 +61,18 @@ client c1 {
 	expect resp.status == 200
 	expect resp.http.tilde0 == "barbaz"
 	expect resp.http.tilde1 == "bar"
+	expect resp.http.tildesub == "barbazbar"
 	expect resp.http.neg0 == "barbaz"
 	expect resp.http.neg1 == "bar"
+	expect resp.http.negsub == "barbazbar"
 	expect resp.http.regsub == "baz"
 	expect resp.http.regsub0 == "barbaz"
 	expect resp.http.regsub1 == "bar"
+	expect resp.http.regsubsub == "barbazbar"
 	expect resp.http.regsuball == "xxxxxx"
 	expect resp.http.regsuball0 == "barbaz"
 	expect resp.http.regsuball1 == "bar"
+	expect resp.http.regsuballsub == "barbazbar"
 } -run
 
 # Function interface
@@ -106,4 +118,18 @@ varnish v1 -vcl+backend {
 
 }
 
-client c1 -run
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.http.tilde0 == "barbaz"
+	expect resp.http.tilde1 == "bar"
+	expect resp.http.neg0 == "barbaz"
+	expect resp.http.neg1 == "bar"
+	expect resp.http.regsub == "baz"
+	expect resp.http.regsub0 == "barbaz"
+	expect resp.http.regsub1 == "bar"
+	expect resp.http.regsuball == "xxxxxx"
+	expect resp.http.regsuball0 == "barbaz"
+	expect resp.http.regsuball1 == "bar"
+} -run