use xstrfmt to replace xmalloc + strcpy/strcat

It's easy to get manual allocation calculations wrong, and
the use of strcpy/strcat raise red flags for people looking
for buffer overflows (though in this case each site was
fine).

It's also shorter to use xstrfmt, and the printf-format
tends to be easier for a reader to see what the final string
will look like.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 5 deletions

diff --git a/shell.c b/shell.c
index 5c0d47a..ace62e4 100644
--- a/shell.c
+++ b/shell.c
@@ -46,11 +46,7 @@ static int is_valid_cmd_name(const char *cmd)
 
 static char *make_cmd(const char *prog)
 {
-	char *prefix = xmalloc((strlen(prog) + strlen(COMMAND_DIR) + 2));
-	strcpy(prefix, COMMAND_DIR);
-	strcat(prefix, "/");
-	strcat(prefix, prog);
-	return prefix;
+	return xstrfmt("%s/%s", COMMAND_DIR, prog);
 }
 
 static void cd_to_homedir(void)