patch-ids: make commit_patch_id() a public helper function

Make commit_patch_id() available to other builtins.

Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

patch-ids.c

diff --git a/patch-ids.c b/patch-ids.c
index b7b3e5a..a4d0016 100644
--- a/patch-ids.c
+++ b/patch-ids.c
@@ -4,7 +4,7 @@
 #include "sha1-lookup.h"
 #include "patch-ids.h"
 
-static int commit_patch_id(struct commit *commit, struct diff_options *options,
+int commit_patch_id(struct commit *commit, struct diff_options *options,
 		    unsigned char *sha1)
 {
 	if (commit->parents)

patch-ids.h

diff --git a/patch-ids.h b/patch-ids.h
index c8c7ca1..eeb56b3 100644
--- a/patch-ids.h
+++ b/patch-ids.h
@@ -13,6 +13,8 @@
 	struct patch_id_bucket *patches;
 };
 
+int commit_patch_id(struct commit *commit, struct diff_options *options,
+		    unsigned char *sha1);
 int init_patch_ids(struct patch_ids *);
 int free_patch_ids(struct patch_ids *);
 struct patch_id *add_commit_patch_id(struct commit *, struct patch_ids *);