connect: split ssh option computation to its own function

This puts the determination of options to pass to each ssh variant
(see ssh.variant in git-config(1)) in one place.

A follow-up patch will use this in an initial dry run to detect which
variant to use when the ssh command is ambiguous.

No functional change intended yet.

Signed-off-by: Jonathan Nieder <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jrn

connect.c

@@ -919,6 +919,42 @@ static struct child_process *git_connect_git(int fd[2], char *hostandport,
 	return conn;
 }
 
+/*
+ * Append the appropriate environment variables to `env` and options to
+ * `args` for running ssh in Git's SSH-tunneled transport.
+ */
+static void push_ssh_options(struct argv_array *args, struct argv_array *env,
+			     enum ssh_variant variant, const char *port,
+			     int flags)
+{
+	if (variant == VARIANT_SSH &&
+	    get_protocol_version_config() > 0) {
+		argv_array_push(args, "-o");
+		argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
+		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
+				 get_protocol_version_config());
+	}
+
+	if (variant != VARIANT_SIMPLE) {
+		if (flags & CONNECT_IPV4)
+			argv_array_push(args, "-4");
+		else if (flags & CONNECT_IPV6)
+			argv_array_push(args, "-6");
+	}
+
+	if (variant == VARIANT_TORTOISEPLINK)
+		argv_array_push(args, "-batch");
+
+	if (port && variant != VARIANT_SIMPLE) {
+		if (variant == VARIANT_SSH)
+			argv_array_push(args, "-p");
+		else
+			argv_array_push(args, "-P");
+
+		argv_array_push(args, port);
+	}
+}
+
 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
 			  const char *port, int flags)
@@ -947,34 +983,7 @@ static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
 	}
 
 	argv_array_push(&conn->args, ssh);
-
-	if (variant == VARIANT_SSH &&
-	    get_protocol_version_config() > 0) {
-		argv_array_push(&conn->args, "-o");
-		argv_array_push(&conn->args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
-		argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
-				 get_protocol_version_config());
-	}
-
-	if (variant != VARIANT_SIMPLE) {
-		if (flags & CONNECT_IPV4)
-			argv_array_push(&conn->args, "-4");
-		else if (flags & CONNECT_IPV6)
-			argv_array_push(&conn->args, "-6");
-	}
-
-	if (variant == VARIANT_TORTOISEPLINK)
-		argv_array_push(&conn->args, "-batch");
-
-	if (port && variant != VARIANT_SIMPLE) {
-		if (variant == VARIANT_SSH)
-			argv_array_push(&conn->args, "-p");
-		else
-			argv_array_push(&conn->args, "-P");
-
-		argv_array_push(&conn->args, port);
-	}
-
+	push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
 	argv_array_push(&conn->args, ssh_host);
 }