From 3fdc27f1e0e9d20789e5c53fdb5d51fc7a3a0e2f Mon Sep 17 00:00:00 2001
From: Nils Goroll <nils.goroll@uplex.de>
Date: Wed, 21 May 2025 10:23:13 +0200
Subject: [PATCH] Start making vtest command arguments less positional

Our common pattern of argument parsing is basically

	for (; *av != NULL; av++) {
		// parse first set of arguments
		if (unknown_argument)
			break;
	}
	for (; *av != NULL; av++) {
		// parse second set of arguments
		if (unknown_argument)
			break;
	}
	// ...

This makes vtest command arguments "semi-positional": Within each set,
they behave like named arguments, but once parsing progressed to the
next set, they behave like positional arguments. This is explicitly
mentioned in the documentation, for example for txreq/txresp:

	"These three switches can appear in any order but must come
	 before the following ones."

While properly documented, this is un-POLA behavior.

This patch changes this behavior for the first set of txreq/txresp
arguments in a simplistic way by filtering known arguments out of the
argument vector. The drawback of the simplistic approach is that
argument values of a "later stage" can not be the same string as
argument names of an "earlier stage". For example, the following would
no onger work:

	txreq -body -nouseragent
---
 src/vtc_http.c   | 35 +++++++++++++++++++++++++++++++++--
 tests/a00024.vtc |  3 ++-
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/vtc_http.c b/src/vtc_http.c
index a5f70186..a9af69fb 100644
--- a/src/vtc_http.c
+++ b/src/vtc_http.c
@@ -1210,6 +1210,32 @@ cmd_http_rxchunk(CMD_ARGS)
  * Transmit a request
  */
 
+struct args {
+      char **argv;
+      int argc;
+};
+
+static void
+args_init(struct args *args)
+{
+	memset(args, 0, sizeof *args);
+}
+
+static void
+args_add(struct args *args, char *arg)
+{
+	AN(args);
+	args->argv = realloc(args->argv, (args->argc + 1) * sizeof *args->argv);
+	AN(args->argv);
+	args->argv[args->argc++] = arg;
+}
+
+static void
+args_free(struct args *args)
+{
+	free(args->argv);
+}
+
 static void
 cmd_http_txreq(CMD_ARGS)
 {
@@ -1218,6 +1244,7 @@ cmd_http_txreq(CMD_ARGS)
 	const char *url = "/";
 	const char *proto = "HTTP/1.1";
 	const char *up = NULL;
+	struct args args;
 	unsigned nohost;
 	unsigned nouseragent = 0;
 
@@ -1228,6 +1255,7 @@ cmd_http_txreq(CMD_ARGS)
 	av++;
 
 	VSB_clear(hp->vsb);
+	args_init(&args);
 
 	hp->head_method = 0;
 	for (; *av != NULL; av++) {
@@ -1248,17 +1276,19 @@ cmd_http_txreq(CMD_ARGS)
 		} else if (!strcmp(*av, "-nouseragent")) {
 			nouseragent = 1;
 		} else
-			break;
+			args_add(&args, *av);
 	}
 	VSB_printf(hp->vsb, "%s %s %s%s", req, url, proto, nl);
 
+	args_add(&args, NULL);
+
 	if (up)
 		VSB_printf(hp->vsb, "Connection: Upgrade, HTTP2-Settings%s"
 				"Upgrade: h2c%s"
 				"HTTP2-Settings: %s%s", nl, nl, up, nl);
 
 	nohost = strcmp(proto, "HTTP/1.1") != 0;
-	av = http_tx_parse_args(av, vl, hp, NULL, nohost, 1, 1, nouseragent);
+	av = http_tx_parse_args(args.argv, vl, hp, NULL, nohost, 1, 1, nouseragent);
 	if (*av != NULL)
 		vtc_fatal(hp->vl, "Unknown http txreq spec: %s\n", *av);
 	http_write(hp, 4, "txreq");
@@ -1282,6 +1312,7 @@ cmd_http_txreq(CMD_ARGS)
 		    "} -start\n"
 		);
 	}
+	args_free(&args);
 }
 
 /* SECTION: client-server.spec.recv
diff --git a/tests/a00024.vtc b/tests/a00024.vtc
index 89a11b43..f5296aef 100644
--- a/tests/a00024.vtc
+++ b/tests/a00024.vtc
@@ -17,6 +17,7 @@ server s2  {
 	txresp
 	rxreq
 	# default User-Agent header is not included when -nouseragent is specified
+	expect req.http.foo == bar
 	expect req.http.User-Agent == <undef>
 	txresp -noserver
 } -start
@@ -36,7 +37,7 @@ client c202 -connect ${s2_sock} {
 	txreq
 	rxresp
 	expect resp.http.Server == "s2"
-	txreq -nouseragent
+	txreq -hdr "foo: bar" -nouseragent
 	rxresp
 	# default Server header is not included when -noserver is specified
 	expect resp.http.Server == <undef>