use strip_suffix instead of ends_with in simple cases

When stripping a suffix like:

  if (ends_with(str, "foo"))
	buf = xmemdupz(str, strlen(str) - 3);

we can instead use strip_suffix to avoid the constant 3,
which must match the literal "foo" (we sometimes use
strlen("foo") instead, but that means we are repeating
ourselves). The example above becomes:

  if (strip_suffix(str, "foo", &len))
	buf = xmemdupz(str, len);

This also saves a strlen(), since we calculate the string
length when detecting the suffix.

Note that in some cases we also switch from xstrndup to
xmemdupz, which saves a further strlen call.

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

1 files changed, 2 insertions, 3 deletions

diff --git a/help.c b/help.c
index 372728fe7e..97567c4523 100644
--- a/help.c
+++ b/help.c
@@ -145,7 +145,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 	len = buf.len;
 
 	while ((de = readdir(dir)) != NULL) {
-		int entlen;
+		size_t entlen;
 
 		if (!starts_with(de->d_name, prefix))
 			continue;
@@ -156,8 +156,7 @@ static void list_commands_in_dir(struct cmdnames *cmds,
 			continue;
 
 		entlen = strlen(de->d_name) - prefix_len;
-		if (ends_with(de->d_name, ".exe"))
-			entlen -= 4;
+		strip_suffix(de->d_name, ".exe", &entlen);
 
 		add_cmdname(cmds, de->d_name + prefix_len, entlen);
 	}