builtin/cat-file: let the oid determine the output algorithm

Use GET_OID_HASH_ANY when calling get_oid_with_context.  This
implements the semi-obvious behaviour that specifying a sha1 oid shows
the output for a sha1 encoded object, and specifying a sha256 oid
shows the output for a sha256 encoded object.

This is useful for testing the the conversion of an object to an
equivalent object encoded with a different hash function.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 694c8538df2ff8200e214351e5e857530d2a1191..e615d1f8e0da2605ab026a3fe2ffc3c8c1b4fbf5 100644 (file)
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -107,7 +107,10 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
        struct object_info oi = OBJECT_INFO_INIT;
        struct strbuf sb = STRBUF_INIT;
        unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
-       unsigned get_oid_flags = GET_OID_RECORD_PATH | GET_OID_ONLY_TO_DIE;
+       unsigned get_oid_flags =
+               GET_OID_RECORD_PATH |
+               GET_OID_ONLY_TO_DIE |
+               GET_OID_HASH_ANY;
        const char *path = force_path;
        const int opt_cw = (opt == 'c' || opt == 'w');
        if (!path && opt_cw)
@@ -223,7 +226,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
                                                                     &size);
                                const char *target;
                                if (!skip_prefix(buffer, "object ", &target) ||
-                                   get_oid_hex(target, &blob_oid))
+                                   get_oid_hex_algop(target, &blob_oid,
+                                                     &hash_algos[oid.algo]))
                                        die("%s not a valid tag", oid_to_hex(&oid));
                                free(buffer);
                        } else
@@ -512,7 +516,9 @@ static void batch_one_object(const char *obj_name,
                             struct expand_data *data)
 {
        struct object_context ctx;
-       int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
+       int flags =
+               GET_OID_HASH_ANY |
+               (opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0);
        enum get_oid_result result;
 
        result = get_oid_with_context(the_repository, obj_name,