t: use test_decode_color rather than literal ANSI codes

diff --git a/builtin/grep.c b/builtin/grep.c
index fa351c49f4fd74b3cde1703ef98dba5f0c2c4e8f..0d6e669732dadd574c69924578bf85ed6e6aeaf8 100644 (file)
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -543,7 +543,7 @@ static void compile_submodule_options(const struct grep_opt *opt,
         * submodule process has its own thread pool.
         */
        argv_array_pushf(&submodule_options, "--threads=%d",
-                        (num_threads + 1) / 2);
+                        DIV_ROUND_UP(num_threads, 2));
 
        /* Add Pathspecs */
        argv_array_push(&submodule_options, "--");