refspec: let callers pass in hash algorithm when parsing items

When parsing a refspec item we need to know about the hash algorithm
used by the repository so that we can decide whether or not a given
string is an exact object ID. We use `the_hash_algo` for this, which
makes the code implicitly depend on `the_repository`.

Refactor `refspec_item_init_fetch()`, `refspec_item_init_push()` and
`valid_fetch_refspec()` so that callers have to pass in the hash
algorithm explicitly and adapt callers accordingly. For now, all of
the callers simply pass `the_hash_algo`, so there is no change in
behaviour.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -601,7 +601,8 @@ static struct ref *get_ref_map(struct remote *remote,
 		struct refspec_item tag_refspec;
 
 		/* also fetch all tags */
-		refspec_item_init_push(&tag_refspec, TAG_REFSPEC);
+		refspec_item_init_push(&tag_refspec, TAG_REFSPEC,
+				       the_hash_algo);
 		get_fetch_map(remote_refs, &tag_refspec, &tail, 0);
 		refspec_item_clear(&tag_refspec);
 	} else if (tags == TAGS_DEFAULT && *autotags) {

builtin/pull.c

@@ -612,7 +612,7 @@ static const char *get_tracking_branch(const char *remote, const char *refspec)
 	const char *spec_src;
 	const char *merge_branch;
 
-	if (!refspec_item_init_fetch(&spec, refspec))
+	if (!refspec_item_init_fetch(&spec, refspec, the_hash_algo))
 		die(_("invalid refspec '%s'"), refspec);
 	spec_src = spec.src;
 	if (!*spec_src || !strcmp(spec_src, "HEAD"))

refspec.c

@@ -16,7 +16,8 @@
  * Parses the provided refspec 'refspec' and populates the refspec_item 'item'.
  * Returns 1 if successful and 0 if the refspec is invalid.
  */
-static int parse_refspec(struct refspec_item *item, const char *refspec, int fetch)
+static int parse_refspec(struct refspec_item *item, const char *refspec,
+			 const struct git_hash_algo *algo, int fetch)
 {
 	size_t llen;
 	int is_glob;
@@ -84,7 +85,7 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 		 */
 		if (!*item->src)
 			return 0; /* negative refspecs must not be empty */
-		else if (llen == the_hash_algo->hexsz && !get_oid_hex(item->src, &unused))
+		else if (llen == algo->hexsz && !get_oid_hex_algop(item->src, &unused, algo))
 			return 0; /* negative refspecs cannot be exact sha1 */
 		else if (!check_refname_format(item->src, flags))
 			; /* valid looking ref is ok */
@@ -101,7 +102,7 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 		/* LHS */
 		if (!*item->src)
 			; /* empty is ok; it means "HEAD" */
-		else if (llen == the_hash_algo->hexsz && !get_oid_hex(item->src, &unused))
+		else if (llen == algo->hexsz && !get_oid_hex_algop(item->src, &unused, algo))
 			item->exact_sha1 = 1; /* ok */
 		else if (!check_refname_format(item->src, flags))
 			; /* valid looking ref is ok */
@@ -154,21 +155,23 @@ static int parse_refspec(struct refspec_item *item, const char *refspec, int fet
 }
 
 static int refspec_item_init(struct refspec_item *item, const char *refspec,
-			     int fetch)
+			     const struct git_hash_algo *algo, int fetch)
 {
 	memset(item, 0, sizeof(*item));
 	item->raw = xstrdup(refspec);
-	return parse_refspec(item, refspec, fetch);
+	return parse_refspec(item, refspec, algo, fetch);
 }
 
-int refspec_item_init_fetch(struct refspec_item *item, const char *refspec)
+int refspec_item_init_fetch(struct refspec_item *item, const char *refspec,
+			    const struct git_hash_algo *algo)
 {
-	return refspec_item_init(item, refspec, 1);
+	return refspec_item_init(item, refspec, algo, 1);
 }
 
-int refspec_item_init_push(struct refspec_item *item, const char *refspec)
+int refspec_item_init_push(struct refspec_item *item, const char *refspec,
+			   const struct git_hash_algo *algo)
 {
-	return refspec_item_init(item, refspec, 0);
+	return refspec_item_init(item, refspec, algo, 0);
 }
 
 void refspec_item_clear(struct refspec_item *item)
@@ -200,9 +203,9 @@ void refspec_append(struct refspec *rs, const char *refspec)
 	int ret;
 
 	if (rs->fetch)
-		ret = refspec_item_init_fetch(&item, refspec);
+		ret = refspec_item_init_fetch(&item, refspec, the_hash_algo);
 	else
-		ret = refspec_item_init_push(&item, refspec);
+		ret = refspec_item_init_push(&item, refspec, the_hash_algo);
 	if (!ret)
 		die(_("invalid refspec '%s'"), refspec);
 
@@ -246,10 +249,11 @@ void refspec_clear(struct refspec *rs)
 	rs->fetch = 0;
 }
 
-int valid_fetch_refspec(const char *fetch_refspec_str)
+int valid_fetch_refspec(const char *fetch_refspec_str,
+			const struct git_hash_algo *algo)
 {
 	struct refspec_item refspec;
-	int ret = refspec_item_init_fetch(&refspec, fetch_refspec_str);
+	int ret = refspec_item_init_fetch(&refspec, fetch_refspec_str, algo);
 	refspec_item_clear(&refspec);
 	return ret;
 }

refspec.h

@@ -1,6 +1,7 @@
 #ifndef REFSPEC_H
 #define REFSPEC_H
 
+struct git_hash_algo;
 struct string_list;
 struct strvec;
 
@@ -33,8 +34,10 @@ struct refspec_item {
 	char *raw;
 };
 
-int refspec_item_init_fetch(struct refspec_item *item, const char *refspec);
-int refspec_item_init_push(struct refspec_item *item, const char *refspec);
+int refspec_item_init_fetch(struct refspec_item *item, const char *refspec,
+			    const struct git_hash_algo *algo);
+int refspec_item_init_push(struct refspec_item *item, const char *refspec,
+			   const struct git_hash_algo *algo);
 void refspec_item_clear(struct refspec_item *item);
 
 /**
@@ -61,7 +64,7 @@ __attribute__((format (printf,2,3)))
 void refspec_appendf(struct refspec *rs, const char *fmt, ...);
 void refspec_appendn(struct refspec *rs, const char **refspecs, int nr);
 
-int valid_fetch_refspec(const char *refspec);
+int valid_fetch_refspec(const char *refspec, const struct git_hash_algo *algo);
 
 /*
  * Determine what <prefix> values to pass to the peer in ref-prefix lines

remote.c

@@ -3039,7 +3039,7 @@ int valid_remote_name(const char *name)
 	int result;
 	struct strbuf refspec = STRBUF_INIT;
 	strbuf_addf(&refspec, "refs/heads/test:refs/remotes/%s/test", name);
-	result = valid_fetch_refspec(refspec.buf);
+	result = valid_fetch_refspec(refspec.buf, the_hash_algo);
 	strbuf_release(&refspec);
 	return result;
 }