sha1-name: introduce a get_oid() function

The get_oid() function is equivalent to the get_sha1() function, but
uses a struct object_id instead.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -1124,6 +1124,8 @@ extern int get_sha1_blob(const char *str, unsigned char *sha1);
 extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
 extern int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc);
 
+extern int get_oid(const char *str, struct object_id *oid);
+
 typedef int each_abbrev_fn(const unsigned char *sha1, void *);
 extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);
 

sha1_name.c

@@ -1214,6 +1214,15 @@ int get_sha1(const char *name, unsigned char *sha1)
 	return get_sha1_with_context(name, 0, sha1, &unused);
 }
 
+/*
+ * This is like "get_sha1()", but for struct object_id.
+ */
+int get_oid(const char *name, struct object_id *oid)
+{
+	return get_sha1(name, oid->hash);
+}
+
+
 /*
  * Many callers know that the user meant to name a commit-ish by
  * syntactical positions where the object name appears.  Calling this