use child_process member "args" instead of string array variable

Use run_command() with a struct child_process variable and populate its
"args" member directly instead of building a string array and passing it
to run_command_v_opt().  This avoids the use of magic index numbers and
makes simplifies the possible addition of more arguments in the future.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

builtin/difftool.c

@@ -360,8 +360,8 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 	struct pair_entry *entry;
 	struct index_state wtindex;
 	struct checkout lstate, rstate;
-	int flags = RUN_GIT_CMD, err = 0;
-	const char *helper_argv[] = { "difftool--helper", NULL, NULL, NULL };
+	int err = 0;
+	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct hashmap wt_modified, tmp_modified;
 	int indices_loaded = 0;
 
@@ -563,16 +563,17 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 	}
 
 	strbuf_setlen(&ldir, ldir_len);
-	helper_argv[1] = ldir.buf;
 	strbuf_setlen(&rdir, rdir_len);
-	helper_argv[2] = rdir.buf;
 
 	if (extcmd) {
-		helper_argv[0] = extcmd;
-		flags = 0;
-	} else
+		strvec_push(&cmd.args, extcmd);
+	} else {
+		strvec_push(&cmd.args, "difftool--helper");
+		cmd.git_cmd = 1;
 		setenv("GIT_DIFFTOOL_DIRDIFF", "true", 1);
-	ret = run_command_v_opt(helper_argv, flags);
+	}
+	strvec_pushl(&cmd.args, ldir.buf, rdir.buf, NULL);
+	ret = run_command(&cmd);
 
 	/* TODO: audit for interaction with sparse-index. */
 	ensure_full_index(&wtindex);

builtin/merge.c

@@ -347,33 +347,25 @@ out:
 
 static void read_empty(const struct object_id *oid)
 {
-	int i = 0;
-	const char *args[7];
-
-	args[i++] = "read-tree";
-	args[i++] = "-m";
-	args[i++] = "-u";
-	args[i++] = empty_tree_oid_hex();
-	args[i++] = oid_to_hex(oid);
-	args[i] = NULL;
+	struct child_process cmd = CHILD_PROCESS_INIT;
+
+	strvec_pushl(&cmd.args, "read-tree", "-m", "-u", empty_tree_oid_hex(),
+		     oid_to_hex(oid), NULL);
+	cmd.git_cmd = 1;
 
-	if (run_command_v_opt(args, RUN_GIT_CMD))
+	if (run_command(&cmd))
 		die(_("read-tree failed"));
 }
 
 static void reset_hard(const struct object_id *oid)
 {
-	int i = 0;
-	const char *args[6];
-
-	args[i++] = "read-tree";
-	args[i++] = "-v";
-	args[i++] = "--reset";
-	args[i++] = "-u";
-	args[i++] = oid_to_hex(oid);
-	args[i] = NULL;
+	struct child_process cmd = CHILD_PROCESS_INIT;
+
+	strvec_pushl(&cmd.args, "read-tree", "-v", "--reset", "-u",
+		     oid_to_hex(oid), NULL);
+	cmd.git_cmd = 1;
 
-	if (run_command_v_opt(args, RUN_GIT_CMD))
+	if (run_command(&cmd))
 		die(_("read-tree failed"));
 }
 

builtin/remote.c

@@ -92,13 +92,15 @@ static int verbose;
 
 static int fetch_remote(const char *name)
 {
-	const char *argv[] = { "fetch", name, NULL, NULL };
-	if (verbose) {
-		argv[1] = "-v";
-		argv[2] = name;
-	}
+	struct child_process cmd = CHILD_PROCESS_INIT;
+
+	strvec_push(&cmd.args, "fetch");
+	if (verbose)
+		strvec_push(&cmd.args, "-v");
+	strvec_push(&cmd.args, name);
+	cmd.git_cmd = 1;
 	printf_ln(_("Updating %s"), name);
-	if (run_command_v_opt(argv, RUN_GIT_CMD))
+	if (run_command(&cmd))
 		return error(_("Could not fetch %s"), name);
 	return 0;
 }

compat/mingw.c

@@ -196,16 +196,19 @@ static int read_yes_no_answer(void)
 static int ask_yes_no_if_possible(const char *format, ...)
 {
 	char question[4096];
-	const char *retry_hook[] = { NULL, NULL, NULL };
+	const char *retry_hook;
 	va_list args;
 
 	va_start(args, format);
 	vsnprintf(question, sizeof(question), format, args);
 	va_end(args);
 
-	if ((retry_hook[0] = mingw_getenv("GIT_ASK_YESNO"))) {
-		retry_hook[1] = question;
-		return !run_command_v_opt(retry_hook, 0);
+	retry_hook = mingw_getenv("GIT_ASK_YESNO");
+	if (retry_hook) {
+		struct child_process cmd = CHILD_PROCESS_INIT;
+
+		strvec_pushl(&cmd.args, retry_hook, question, NULL);
+		return !run_command(&cmd);
 	}
 
 	if (!isatty(_fileno(stdin)) || !isatty(_fileno(stderr)))

ll-merge.c

@@ -193,7 +193,7 @@ static enum ll_merge_result ll_ext_merge(const struct ll_merge_driver *fn,
 	struct strbuf cmd = STRBUF_INIT;
 	struct strbuf_expand_dict_entry dict[6];
 	struct strbuf path_sq = STRBUF_INIT;
-	const char *args[] = { NULL, NULL };
+	struct child_process child = CHILD_PROCESS_INIT;
 	int status, fd, i;
 	struct stat st;
 	enum ll_merge_result ret;
@@ -219,8 +219,9 @@ static enum ll_merge_result ll_ext_merge(const struct ll_merge_driver *fn,
 
 	strbuf_expand(&cmd, fn->cmdline, strbuf_expand_dict_cb, &dict);
 
-	args[0] = cmd.buf;
-	status = run_command_v_opt(args, RUN_USING_SHELL);
+	child.use_shell = 1;
+	strvec_push(&child.args, cmd.buf);
+	status = run_command(&child);
 	fd = open(temp[1], O_RDONLY);
 	if (fd < 0)
 		goto bad;

t/helper/test-fake-ssh.c

@@ -8,7 +8,7 @@ int cmd_main(int argc, const char **argv)
 	struct strbuf buf = STRBUF_INIT;
 	FILE *f;
 	int i;
-	const char *child_argv[] = { NULL, NULL };
+	struct child_process cmd = CHILD_PROCESS_INIT;
 
 	/* First, print all parameters into $TRASH_DIRECTORY/ssh-output */
 	if (!trash_directory)
@@ -25,6 +25,7 @@ int cmd_main(int argc, const char **argv)
 	/* Now, evaluate the *last* parameter */
 	if (argc < 2)
 		return 0;
-	child_argv[0] = argv[argc - 1];
-	return run_command_v_opt(child_argv, RUN_USING_SHELL);
+	cmd.use_shell = 1;
+	strvec_push(&cmd.args, argv[argc - 1]);
+	return run_command(&cmd);
 }