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>

1 files changed, 9 insertions, 8 deletions

diff --git a/builtin/difftool.c b/builtin/difftool.c
index 4b10ad1a36..22bcc3444b 100644
--- a/builtin/difftool.c
+++ b/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);