Add an optional argument to the debug.argtest function

bin/varnishtest/tests/m00019.vtc

@@ -24,6 +24,7 @@ varnish v1 -vcl+backend {
 		set resp.http.foo4 = debug.argtest("1", 2.4, three="3d", four=-1);
 		set resp.http.foo5 = debug.argtest("1", 2.5);
 		set resp.http.foo6 = debug.argtest("1", four=6);
+		set resp.http.foo7 = debug.argtest("1", opt="7");
 
 		set resp.http.obj0 = obj0.string() + ", " + obj0.number();
 		set resp.http.obj1 = obj1.string() + ", " + obj1.number();
@@ -38,12 +39,13 @@ client c1 {
 	txreq
 	rxresp
 	expect resp.bodylen == "6"
-	expect resp.http.foo1 == "1 2.1 3a , 4"
-	expect resp.http.foo2 == "1 -2.2 3b , 4"
-	expect resp.http.foo3 == "1 2.3 3c , 4"
-	expect resp.http.foo4 == "1 2.4 3d , -1"
-	expect resp.http.foo5 == "1 2.5 3 , 4"
-	expect resp.http.foo6 == "1 2 3 , 6"
+	expect resp.http.foo1 == "1 2.1 3a , 4 0 <undef>"
+	expect resp.http.foo2 == "1 -2.2 3b , 4 0 <undef>"
+	expect resp.http.foo3 == "1 2.3 3c , 4 0 <undef>"
+	expect resp.http.foo4 == "1 2.4 3d , -1 0 <undef>"
+	expect resp.http.foo5 == "1 2.5 3 , 4 0 <undef>"
+	expect resp.http.foo6 == "1 2 3 , 6 0 <undef>"
+	expect resp.http.foo7 == "1 2 3 , 4 1 7"
 
 	expect resp.http.obj0 == "default, one"
 	expect resp.http.obj1 == "only_argument, one"

lib/libvmod_debug/vmod.vcc

@@ -117,7 +117,9 @@ Encrypt the HTTP header with quad-ROT13 encryption,
 
 $Function STRING argtest(
 	  STRING one, REAL two =2, STRING three= "3",
-	  STRING comma="," , INT four = 4 )
+	  STRING comma=",", INT four = 4,
+	  [ STRING opt]
+)
 
 $Function INT vre_limit()
 

lib/libvmod_debug/vmod_debug.c

@@ -151,12 +151,14 @@ xyzzy_rot52(VRT_CTX, VCL_HTTP hp)
 }
 
 VCL_STRING v_matchproto_(td_debug_argtest)
-xyzzy_argtest(VRT_CTX, VCL_STRING one, VCL_REAL two, VCL_STRING three,
-    VCL_STRING comma, VCL_INT four)
+xyzzy_argtest(VRT_CTX, struct xyzzy_argtest_arg *arg)
 {
 	char buf[100];
 
-	bprintf(buf, "%s %g %s %s %ld", one, two, three, comma, four);
+	AN(arg);
+	bprintf(buf, "%s %g %s %s %ld %d %s",
+	    arg->one, arg->two, arg->three, arg->comma, arg->four,
+	    arg->valid_opt, arg->valid_opt ? arg->opt : "<undef>");
 	return (WS_Copy(ctx->ws, buf, -1));
 }