Merge branch 'maint'

* maint:
  gitweb: use decode_utf8 directly
  posix compatibility for t4200
  Document 'opendiff' value in config.txt and git-mergetool.txt
  Allow PERL_PATH="/usr/bin/env perl"
  Make xstrndup common
  diff.c: fix "size cache" handling.
  http-fetch: Disable use of curl multi support for libcurl < 7.16.

commit.c

@@ -718,14 +718,6 @@ static char *logmsg_reencode(const struct commit *commit,
 	return out;
 }
 
-static char *xstrndup(const char *text, int len)
-{
-	char *result = xmalloc(len + 1);
-	memcpy(result, text, len);
-	result[len] = '\0';
-	return result;
-}
-
 static void fill_person(struct interp *table, const char *msg, int len)
 {
 	int start, end, tz = 0;