Make -msg an alias to -reason

When we renamed resp.msg to resp.reason to match RFC and VCL terminology
we forgot to rename its counterpart. Instead of renaming -msg to -reason
the former will instead become an alias of the latter. This way it can
be applied to older branches (modulus inline documentation).

bin/varnishtest/tests/a00002.vtc

@@ -5,7 +5,7 @@ server s1 {
 	expect req.method == PUT
 	expect req.proto == HTTP/1.0
 	expect req.url == "/foo"
-	txresp -proto HTTP/1.2 -status 201 -msg Foo
+	txresp -proto HTTP/1.2 -status 201 -reason Foo
 }
 
 server s1 -start

bin/varnishtest/tests/a00003.vtc

@@ -5,7 +5,7 @@ server s1 {
 	expect req.method == PUT
 	expect req.proto == HTTP/1.0
 	expect req.url == "/foo"
-	txresp -proto HTTP/1.2 -status 201 -msg Foo
+	txresp -proto HTTP/1.2 -status 201 -reason Foo
 }
 
 server s2 {

bin/varnishtest/tests/a00004.vtc

@@ -5,7 +5,7 @@ server s1 -repeat 2 {
 	expect req.method == PUT
 	expect req.proto == HTTP/1.0
 	expect req.url == "/foo"
-	txresp -proto HTTP/1.2 -status 201 -msg Foo
+	txresp -proto HTTP/1.2 -status 201 -reason Foo
 }
 
 server s1 -start

bin/varnishtest/tests/a00005.vtc

@@ -5,7 +5,7 @@ server s1 {
 	expect req.method == PUT
 	expect req.proto == HTTP/1.0
 	expect req.url == "/foo"
-	txresp -proto HTTP/1.2 -status 201 -msg Foo
+	txresp -proto HTTP/1.2 -status 201 -reason Foo
 }
 
 server s2 {

bin/varnishtest/tests/a00006.vtc

@@ -5,7 +5,7 @@ server s1 {
 	expect req.method == PUT
 	expect req.proto == HTTP/1.0
 	expect req.url == "/foo"
-	txresp -proto HTTP/1.2 -status 201 -msg Foo \
+	txresp -proto HTTP/1.2 -status 201 -reason Foo \
 		-body "987654321\n"
 }
 

bin/varnishtest/tests/r00962.vtc

@@ -38,7 +38,7 @@ varnish v1 -stop
 
 server s1 {
 	rxreq
-	txresp -status 400 -msg "Persistent Object Not Found"
+	txresp -status 400 -reason "Persistent Object Not Found"
 } -start
 
 

bin/varnishtest/tests/r01485.vtc

@@ -6,7 +6,7 @@ server s1 {
 
 	rxreq
 	expect req.http.If-None-Match == {"foo"}
-	txresp -status 304 -msg "Not Modified"
+	txresp -status 304 -reason "Not Modified"
 } -start
 
 varnish v1 -vcl+backend {

bin/varnishtest/vtc_http.c

@@ -823,7 +823,7 @@ cmd_http_txresp(CMD_ARGS)
 	struct http *hp;
 	const char *proto = "HTTP/1.1";
 	const char *status = "200";
-	const char *msg = "OK";
+	const char *reason = "OK";
 	char* body = NULL;
 
 	(void)cmd;
@@ -842,15 +842,15 @@ cmd_http_txresp(CMD_ARGS)
 		} else if (!strcmp(*av, "-status")) {
 			status = av[1];
 			av++;
-		} else if (!strcmp(*av, "-msg")) {
-			msg = av[1];
+		} else if (!strcmp(*av, "-reason") || !strcmp(*av, "-msg")) {
+			reason = av[1];
 			av++;
 			continue;
 		} else
 			break;
 	}
 
-	VSB_printf(hp->vsb, "%s %s %s%s", proto, status, msg, nl);
+	VSB_printf(hp->vsb, "%s %s %s%s", proto, status, reason, nl);
 
 	/* send a "Content-Length: 0" header unless something else happens */
 	REPLACE(body, "");