Merge branch 'bc/hash-transition-part-15'

More codepaths are moving away from hardcoded hash sizes.

* bc/hash-transition-part-15:
  rerere: convert to use the_hash_algo
  submodule: make zero-oid comparison hash function agnostic
  apply: rename new_sha1_prefix and old_sha1_prefix
  apply: replace hard-coded constants
  tag: express constant in terms of the_hash_algo
  transport: use parse_oid_hex instead of a constant
  upload-pack: express constants in terms of the_hash_algo
  refs/packed-backend: express constants using the_hash_algo
  packfile: express constants in terms of the_hash_algo
  pack-revindex: express constants in terms of the_hash_algo
  builtin/fetch-pack: remove constants with parse_oid_hex
  builtin/mktree: remove hard-coded constant
  builtin/repack: replace hard-coded constants
  pack-bitmap-write: use GIT_MAX_RAWSZ for allocation
  object_id.cocci: match only expressions of type 'struct object_id'

Author: gitster

apply.c

@@ -223,8 +223,8 @@ struct patch {
 	struct fragment *fragments;
 	char *result;
 	size_t resultsize;
-	char old_sha1_prefix[41];
-	char new_sha1_prefix[41];
+	char old_oid_prefix[GIT_MAX_HEXSZ + 1];
+	char new_oid_prefix[GIT_MAX_HEXSZ + 1];
 	struct patch *next;
 
 	/* three-way fallback result */
@@ -1093,13 +1093,14 @@ static int gitdiff_index(struct apply_state *state,
 	 */
 	const char *ptr, *eol;
 	int len;
+	const unsigned hexsz = the_hash_algo->hexsz;
 
 	ptr = strchr(line, '.');
-	if (!ptr || ptr[1] != '.' || 40 < ptr - line)
+	if (!ptr || ptr[1] != '.' || hexsz < ptr - line)
 		return 0;
 	len = ptr - line;
-	memcpy(patch->old_sha1_prefix, line, len);
-	patch->old_sha1_prefix[len] = 0;
+	memcpy(patch->old_oid_prefix, line, len);
+	patch->old_oid_prefix[len] = 0;
 
 	line = ptr + 2;
 	ptr = strchr(line, ' ');
@@ -1109,10 +1110,10 @@ static int gitdiff_index(struct apply_state *state,
 		ptr = eol;
 	len = ptr - line;
 
-	if (40 < len)
+	if (hexsz < len)
 		return 0;
-	memcpy(patch->new_sha1_prefix, line, len);
-	patch->new_sha1_prefix[len] = 0;
+	memcpy(patch->new_oid_prefix, line, len);
+	patch->new_oid_prefix[len] = 0;
 	if (*ptr == ' ')
 		return gitdiff_oldmode(state, ptr + 1, patch);
 	return 0;
@@ -2206,7 +2207,7 @@ static void reverse_patches(struct patch *p)
 		SWAP(p->new_mode, p->old_mode);
 		SWAP(p->is_new, p->is_delete);
 		SWAP(p->lines_added, p->lines_deleted);
-		SWAP(p->old_sha1_prefix, p->new_sha1_prefix);
+		SWAP(p->old_oid_prefix, p->new_oid_prefix);
 
 		for (; frag; frag = frag->next) {
 			SWAP(frag->newpos, frag->oldpos);
@@ -3144,15 +3145,16 @@ static int apply_binary(struct apply_state *state,
 {
 	const char *name = patch->old_name ? patch->old_name : patch->new_name;
 	struct object_id oid;
+	const unsigned hexsz = the_hash_algo->hexsz;
 
 	/*
 	 * For safety, we require patch index line to contain
-	 * full 40-byte textual SHA1 for old and new, at least for now.
+	 * full hex textual object ID for old and new, at least for now.
 	 */
-	if (strlen(patch->old_sha1_prefix) != 40 ||
-	    strlen(patch->new_sha1_prefix) != 40 ||
-	    get_oid_hex(patch->old_sha1_prefix, &oid) ||
-	    get_oid_hex(patch->new_sha1_prefix, &oid))
+	if (strlen(patch->old_oid_prefix) != hexsz ||
+	    strlen(patch->new_oid_prefix) != hexsz ||
+	    get_oid_hex(patch->old_oid_prefix, &oid) ||
+	    get_oid_hex(patch->new_oid_prefix, &oid))
 		return error(_("cannot apply binary patch to '%s' "
 			       "without full index line"), name);
 
@@ -3162,7 +3164,7 @@ static int apply_binary(struct apply_state *state,
 		 * applies to.
 		 */
 		hash_object_file(img->buf, img->len, blob_type, &oid);
-		if (strcmp(oid_to_hex(&oid), patch->old_sha1_prefix))
+		if (strcmp(oid_to_hex(&oid), patch->old_oid_prefix))
 			return error(_("the patch applies to '%s' (%s), "
 				       "which does not match the "
 				       "current contents."),
@@ -3175,7 +3177,7 @@ static int apply_binary(struct apply_state *state,
 				       "'%s' but it is not empty"), name);
 	}
 
-	get_oid_hex(patch->new_sha1_prefix, &oid);
+	get_oid_hex(patch->new_oid_prefix, &oid);
 	if (is_null_oid(&oid)) {
 		clear_image(img);
 		return 0; /* deletion patch */
@@ -3191,7 +3193,7 @@ static int apply_binary(struct apply_state *state,
 		if (!result)
 			return error(_("the necessary postimage %s for "
 				       "'%s' cannot be read"),
-				     patch->new_sha1_prefix, name);
+				     patch->new_oid_prefix, name);
 		clear_image(img);
 		img->buf = result;
 		img->len = size;
@@ -3207,9 +3209,9 @@ static int apply_binary(struct apply_state *state,
 
 		/* verify that the result matches */
 		hash_object_file(img->buf, img->len, blob_type, &oid);
-		if (strcmp(oid_to_hex(&oid), patch->new_sha1_prefix))
+		if (strcmp(oid_to_hex(&oid), patch->new_oid_prefix))
 			return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
-				name, patch->new_sha1_prefix, oid_to_hex(&oid));
+				name, patch->new_oid_prefix, oid_to_hex(&oid));
 	}
 
 	return 0;
@@ -3568,7 +3570,7 @@ static int try_threeway(struct apply_state *state,
 	/* Preimage the patch was prepared for */
 	if (patch->is_new)
 		write_object_file("", 0, blob_type, &pre_oid);
-	else if (get_oid(patch->old_sha1_prefix, &pre_oid) ||
+	else if (get_oid(patch->old_oid_prefix, &pre_oid) ||
 		 read_blob_object(&buf, &pre_oid, patch->old_mode))
 		return error(_("repository lacks the necessary blob to fall back on 3-way merge."));
 
@@ -4060,13 +4062,13 @@ static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
 	    starts_with(++preimage, heading) &&
 	    /* does it record full SHA-1? */
 	    !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
-	    preimage[sizeof(heading) + GIT_SHA1_HEXSZ - 1] == '\n' &&
+	    preimage[sizeof(heading) + the_hash_algo->hexsz - 1] == '\n' &&
 	    /* does the abbreviated name on the index line agree with it? */
-	    starts_with(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
+	    starts_with(preimage + sizeof(heading) - 1, p->old_oid_prefix))
 		return 0; /* it all looks fine */
 
 	/* we may have full object name on the index line */
-	return get_oid_hex(p->old_sha1_prefix, oid);
+	return get_oid_hex(p->old_oid_prefix, oid);
 }
 
 /* Build an index that contains just the files needed for a 3way merge */
@@ -4095,7 +4097,7 @@ static int build_fake_ancestor(struct apply_state *state, struct patch *list)
 			else
 				return error(_("sha1 information is lacking or "
 					       "useless for submodule %s"), name);
-		} else if (!get_oid_blob(patch->old_sha1_prefix, &oid)) {
+		} else if (!get_oid_blob(patch->old_oid_prefix, &oid)) {
 			; /* ok */
 		} else if (!patch->lines_added && !patch->lines_deleted) {
 			/* mode-only change: update the current */

builtin/fetch-pack.c

@@ -16,13 +16,14 @@ static void add_sought_entry(struct ref ***sought, int *nr, int *alloc,
 {
 	struct ref *ref;
 	struct object_id oid;
+	const char *p;
 
-	if (!get_oid_hex(name, &oid)) {
-		if (name[GIT_SHA1_HEXSZ] == ' ') {
-			/* <sha1> <ref>, find refname */
-			name += GIT_SHA1_HEXSZ + 1;
-		} else if (name[GIT_SHA1_HEXSZ] == '\0') {
-			; /* <sha1>, leave sha1 as name */
+	if (!parse_oid_hex(name, &oid, &p)) {
+		if (*p == ' ') {
+			/* <oid> <ref>, find refname */
+			name = p + 1;
+		} else if (*p == '\0') {
+			; /* <oid>, leave oid as name */
 		} else {
 			/* <ref>, clear cruft from oid */
 			oidclr(&oid);

builtin/mktree.c

@@ -98,7 +98,7 @@ static void mktree_line(char *buf, size_t len, int nul_term_line, int allow_miss
 
 	*ntr++ = 0; /* now at the beginning of SHA1 */
 
-	path = ntr + 41;  /* at the beginning of name */
+	path = (char *)p + 1;  /* at the beginning of name */
 	if (!nul_term_line && path[0] == '"') {
 		struct strbuf p_uq = STRBUF_INIT;
 		if (unquote_c_style(&p_uq, path, NULL))

builtin/repack.c

@@ -235,8 +235,8 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 	while (strbuf_getline_lf(&line, out) != EOF) {
 		char *promisor_name;
 		int fd;
-		if (line.len != 40)
-			die("repack: Expecting 40 character sha1 lines only from pack-objects.");
+		if (line.len != the_hash_algo->hexsz)
+			die("repack: Expecting full hex object ID lines only from pack-objects.");
 		string_list_append(names, line.buf);
 
 		/*
@@ -407,8 +407,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	out = xfdopen(cmd.out, "r");
 	while (strbuf_getline_lf(&line, out) != EOF) {
-		if (line.len != 40)
-			die("repack: Expecting 40 character sha1 lines only from pack-objects.");
+		if (line.len != the_hash_algo->hexsz)
+			die("repack: Expecting full hex object ID lines only from pack-objects.");
 		string_list_append(&names, line.buf);
 	}
 	fclose(out);
@@ -535,14 +535,15 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	reprepare_packed_git(the_repository);
 
 	if (delete_redundant) {
+		const int hexsz = the_hash_algo->hexsz;
 		int opts = 0;
 		string_list_sort(&names);
 		for_each_string_list_item(item, &existing_packs) {
 			char *sha1;
 			size_t len = strlen(item->string);
-			if (len < 40)
+			if (len < hexsz)
 				continue;
-			sha1 = item->string + len - 40;
+			sha1 = item->string + len - hexsz;
 			if (!string_list_has_string(&names, sha1))
 				remove_redundant_pack(packdir, item->string);
 		}