[PATCH v2 01/43] refs.c: create a public version of verify_refname_available

[David Turner <dturner@twopensource.com>]

From: Ronnie Sahlberg <sahlberg@google.com>

Create a public version of verify_refname_available that backends can
provide.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
---
 refs.c | 51 +++++++++++++++++++++++++++++----------------------
 refs.h | 17 +++++++++++++++++
 2 files changed, 46 insertions(+), 22 deletions(-)

diff --git a/refs.c b/refs.c
index 132eff5..ce551e9 100644
--- a/refs.c
+++ b/refs.c
@@ -279,7 +279,7 @@ struct ref_dir {
  * presence of an empty subdirectory does not block the creation of a
  * similarly-named reference.  (The fact that reference names with the
  * same leading components can conflict *with each other* is a
- * separate issue that is regulated by verify_refname_available().)
+ * separate issue that is regulated by verify_refname_available_dir().)
  *
  * Please note that the name field contains the fully-qualified
  * reference (or subdirectory) name.  Space could be saved by only
@@ -911,11 +911,11 @@ static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
  *
  * extras and skip must be sorted.
  */
-static int verify_refname_available(const char *refname,
-				    const struct string_list *extras,
-				    const struct string_list *skip,
-				    struct ref_dir *dir,
-				    struct strbuf *err)
+static int verify_refname_available_dir(const char *refname,
+					const struct string_list *extras,
+					const struct string_list *skip,
+					struct ref_dir *dir,
+					struct strbuf *err)
 {
 	const char *slash;
 	int pos;
@@ -2464,9 +2464,12 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 		 */
 		strbuf_git_path(&orig_ref_file, "%s", orig_refname);
 		if (remove_empty_directories(&orig_ref_file)) {
+			struct ref_dir *loose_refs;
+			loose_refs = get_loose_refs(&ref_cache);
 			last_errno = errno;
-			if (!verify_refname_available(orig_refname, extras, skip,
-						      get_loose_refs(&ref_cache), err))
+			if (!verify_refname_available_dir(orig_refname, extras,
+							  skip, loose_refs,
+							  err))
 				strbuf_addf(err, "there are still refs under '%s'",
 					    orig_refname);
 			goto error_return;
@@ -2479,8 +2482,9 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	if (!refname) {
 		last_errno = errno;
 		if (last_errno != ENOTDIR ||
-		    !verify_refname_available(orig_refname, extras, skip,
-					      get_loose_refs(&ref_cache), err))
+		    !verify_refname_available_dir(orig_refname, extras, skip,
+						  get_loose_refs(&ref_cache),
+						  err))
 			strbuf_addf(err, "unable to resolve reference %s: %s",
 				    orig_refname, strerror(last_errno));
 
@@ -2493,8 +2497,8 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
 	 * our refname.
 	 */
 	if (is_null_oid(&lock->old_oid) &&
-	    verify_refname_available(refname, extras, skip,
-				     get_packed_refs(&ref_cache), err)) {
+	    verify_refname_available_dir(refname, extras, skip,
+					 get_packed_refs(&ref_cache), err)) {
 		last_errno = ENOTDIR;
 		goto error_return;
 	}
@@ -3127,10 +3131,7 @@ static int rename_ref_available(const char *oldname, const char *newname)
 	int ret;
 
 	string_list_insert(&skip, oldname);
-	ret = !verify_refname_available(newname, NULL, &skip,
-					get_packed_refs(&ref_cache), &err)
-		&& !verify_refname_available(newname, NULL, &skip,
-					     get_loose_refs(&ref_cache), &err);
+	ret = !verify_refname_available(newname, NULL, &skip, &err);
 	if (!ret)
 		error("%s", err.buf);
 
@@ -3299,6 +3300,17 @@ static int should_autocreate_reflog(const char *refname)
 		!strcmp(refname, "HEAD");
 }
 
+int verify_refname_available(const char *newname, struct string_list *extra,
+			     struct string_list *skip, struct strbuf *err)
+{
+	struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
+	struct ref_dir *loose_refs = get_loose_refs(&ref_cache);
+	return verify_refname_available_dir(newname, extra, skip,
+					    packed_refs, err) ||
+		verify_refname_available_dir(newname, extra, skip,
+					     loose_refs, err);
+}
+
 /*
  * Create a reflog for a ref.  If force_create = 0, the reflog will
  * only be created for certain refs (those for which
@@ -4334,8 +4346,6 @@ static int ref_present(const char *refname,
 int initial_ref_transaction_commit(struct ref_transaction *transaction,
 				   struct strbuf *err)
 {
-	struct ref_dir *loose_refs = get_loose_refs(&ref_cache);
-	struct ref_dir *packed_refs = get_packed_refs(&ref_cache);
 	int ret = 0, i;
 	int n = transaction->nr;
 	struct ref_update **updates = transaction->updates;
@@ -4378,10 +4388,7 @@ int initial_ref_transaction_commit(struct ref_transaction *transaction,
 			die("BUG: initial ref transaction with old_sha1 set");
 		if (verify_refname_available(update->refname,
 					     &affected_refnames, NULL,
-					     loose_refs, err) ||
-		    verify_refname_available(update->refname,
-					     &affected_refnames, NULL,
-					     packed_refs, err)) {
+					     err)) {
 			ret = TRANSACTION_NAME_CONFLICT;
 			goto cleanup;
 		}
diff --git a/refs.h b/refs.h
index 6d30c98..79ea220 100644
--- a/refs.h
+++ b/refs.h
@@ -218,6 +218,23 @@ extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct st
 int pack_refs(unsigned int flags);
 
 /*
+ * Return true iff a reference named refname could be created without
+ * conflicting with the name of an existing reference.  If
+ * skip is non-NULL, ignore potential conflicts with refs in skip
+ * (e.g., because they are scheduled for deletion in the same
+ * operation).
+ *
+ * Two reference names conflict if one of them exactly matches the
+ * leading components of the other; e.g., "foo/bar" conflicts with
+ * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
+ * "foo/barbados".
+ *
+ * skip must be sorted.
+ */
+int verify_refname_available(const char *newname, struct string_list *extra,
+			     struct string_list *skip, struct strbuf *err);
+
+/*
  * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
  * REF_NODEREF: act on the ref directly, instead of dereferencing
  *              symbolic references.
-- 
2.4.2.644.g97b850b-twtrsrc