[PATCHv5 2/8] commit.c: new function for looking up a comit by name

["Pat Notz" <patnotz@gmail.com>]

Signed-off-by: Pat Notz <patnotz@gmail.com>
---
 builtin/commit.c |    7 +------
 commit.c         |   13 +++++++++++++
 commit.h         |    1 +
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index bf9fcc1..9fe4bdc 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -896,17 +896,12 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (!use_message && renew_authorship)
 		die("--reset-author can be used only with -C, -c or --amend.");
 	if (use_message) {
-		unsigned char sha1[20];
 		static char utf8[] = "UTF-8";
 		const char *out_enc;
 		char *enc;
 		struct commit *commit;
 
-		if (get_sha1(use_message, sha1))
-			die("could not lookup commit %s", use_message);
-		commit = lookup_commit_reference(sha1);
-		if (!commit || parse_commit(commit))
-			die("could not parse commit %s", use_message);
+		commit = lookup_commit_reference_by_name(use_message);
 
 		enc = get_header(commit, "encoding");
 		enc = enc ? enc : utf8;
diff --git a/commit.c b/commit.c
index 0094ec1..f51098a 100644
--- a/commit.c
+++ b/commit.c
@@ -49,6 +49,19 @@ struct commit *lookup_commit(const unsigned char *sha1)
 	return check_commit(obj, sha1, 0);
 }
 
+struct commit *lookup_commit_reference_by_name(const char *name)
+{
+	unsigned char sha1[20];
+	struct commit *commit;
+
+	if (get_sha1(name, sha1))
+		die("could not lookup commit %s", name);
+	commit = lookup_commit_reference(sha1);
+	if (!commit || parse_commit(commit))
+		die("could not parse commit %s", name);
+	return commit;
+}
+
 static unsigned long parse_commit_date(const char *buf, const char *tail)
 {
 	const char *dateptr;
diff --git a/commit.h b/commit.h
index c246c94..6f4b586 100644
--- a/commit.h
+++ b/commit.h
@@ -36,6 +36,7 @@ struct commit *lookup_commit(const unsigned char *sha1);
 struct commit *lookup_commit_reference(const unsigned char *sha1);
 struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
 					      int quiet);
+struct commit *lookup_commit_reference_by_name(const char *name);
 
 int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size);
 
-- 
1.7.3.1