sha1_name: convert get_sha1* to get_oid*

Now that all the callers of get_sha1 directly or indirectly use struct
object_id, rename the functions starting with get_sha1 to start with
get_oid.  Convert the internals in sha1_name.c to use struct object_id
as well, and eliminate explicit length checks where possible.  Convert a
use of 40 in get_oid_basic to GIT_SHA1_HEXSZ.

Outside of sha1_name.c and cache.h, this transition was made with the
following semantic patch:

@@
expression E1, E2;
@@
- get_sha1(E1, E2.hash)
+ get_oid(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1(E1, E2->hash)
+ get_oid(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2.hash)
+ get_oid_committish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2->hash)
+ get_oid_committish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2.hash)
+ get_oid_treeish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2->hash)
+ get_oid_treeish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2.hash)
+ get_oid_commit(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2->hash)
+ get_oid_commit(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2.hash)
+ get_oid_tree(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2->hash)
+ get_oid_tree(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2.hash)
+ get_oid_blob(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2->hash)
+ get_oid_blob(E1, E2)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3.hash, E4)
+ get_oid_with_context(E1, E2, &E3, E4)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3->hash, E4)
+ get_oid_with_context(E1, E2, E3, E4)

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

revision.c

@@ -1303,7 +1303,7 @@ static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
 		flags ^= UNINTERESTING | BOTTOM;
 		arg++;
 	}
-	if (get_sha1_committish(arg, oid.hash))
+	if (get_oid_committish(arg, &oid))
 		return 0;
 	while (1) {
 		it = get_reference(revs, arg, &oid, 0);
@@ -1467,8 +1467,8 @@ static int handle_dotdot_1(const char *arg, char *dotdot,
 	if (!*b_name)
 		b_name = "HEAD";
 
-	if (get_sha1_with_context(a_name, oc_flags, a_oid.hash, a_oc) ||
-	    get_sha1_with_context(b_name, oc_flags, b_oid.hash, b_oc))
+	if (get_oid_with_context(a_name, oc_flags, &a_oid, a_oc) ||
+	    get_oid_with_context(b_name, oc_flags, &b_oid, b_oc))
 		return -1;
 
 	if (!cant_be_filename) {
@@ -1602,7 +1602,7 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 	if (revarg_opt & REVARG_COMMITTISH)
 		get_sha1_flags |= GET_SHA1_COMMITTISH;
 
-	if (get_sha1_with_context(arg, get_sha1_flags, oid.hash, &oc))
+	if (get_oid_with_context(arg, get_sha1_flags, &oid, &oc))
 		return revs->ignore_missing ? 0 : -1;
 	if (!cant_be_filename)
 		verify_non_filename(revs->prefix, arg);
@@ -2321,7 +2321,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		struct object_id oid;
 		struct object *object;
 		struct object_context oc;
-		if (get_sha1_with_context(revs->def, 0, oid.hash, &oc))
+		if (get_oid_with_context(revs->def, 0, &oid, &oc))
 			diagnose_missing_default(revs->def);
 		object = get_reference(revs, revs->def, &oid, 0);
 		add_pending_object_with_mode(revs, object, revs->def, oc.mode);