[PATCH 2/4] refs.c: add a new update_type field to ref_update

[Stefan Beller <sbeller@google.com>]

From: Ronnie Sahlberg <sahlberg@google.com>

Add a field that describes what type of update this refers to. For now
the only type is UPDATE_SHA1 but we will soon add more types.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
---
 refs.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/refs.c b/refs.c
index f0f0d23..84e086f 100644
--- a/refs.c
+++ b/refs.c
@@ -3516,6 +3516,10 @@ int for_each_reflog(each_ref_fn fn, void *cb_data)
 	return retval;
 }
 
+enum transaction_update_type {
+	UPDATE_SHA1 = 0
+};
+
 /**
  * Information needed for a single ref update.  Set new_sha1 to the
  * new value or to zero to delete the ref.  To check the old value
@@ -3523,6 +3527,7 @@ int for_each_reflog(each_ref_fn fn, void *cb_data)
  * value or to zero to ensure the ref does not exist before update.
  */
 struct ref_update {
+	enum transaction_update_type update_type;
 	unsigned char new_sha1[20];
 	unsigned char old_sha1[20];
 	int flags; /* REF_NODEREF? */
@@ -3583,12 +3588,14 @@ void transaction_free(struct transaction *transaction)
 }
 
 static struct ref_update *add_update(struct transaction *transaction,
-				     const char *refname)
+				     const char *refname,
+				     enum transaction_update_type update_type)
 {
 	size_t len = strlen(refname);
 	struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
 
 	strcpy((char *)update->refname, refname);
+	update->update_type = update_type;
 	ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 	transaction->updates[transaction->nr++] = update;
 	return update;
@@ -3618,7 +3625,7 @@ int transaction_update_ref(struct transaction *transaction,
 		return -1;
 	}
 
-	update = add_update(transaction, refname);
+	update = add_update(transaction, refname, UPDATE_SHA1);
 	hashcpy(update->new_sha1, new_sha1);
 	update->flags = flags;
 	update->have_old = have_old;
@@ -3696,13 +3703,17 @@ static int ref_update_reject_duplicates(struct ref_update **updates, int n,
 
 	assert(err);
 
-	for (i = 1; i < n; i++)
+	for (i = 1; i < n; i++) {
+		if (updates[i - 1]->update_type != UPDATE_SHA1 ||
+		    updates[i]->update_type != UPDATE_SHA1)
+			continue;
 		if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
 			strbuf_addf(err,
 				    "Multiple updates for ref '%s' not allowed.",
 				    updates[i]->refname);
 			return 1;
 		}
+	}
 	return 0;
 }
 
@@ -3734,13 +3745,17 @@ int transaction_commit(struct transaction *transaction,
 		goto cleanup;
 	}
 
-	/* Acquire all locks while verifying old values */
+	/* Acquire all ref locks while verifying old values */
 	for (i = 0; i < n; i++) {
 		struct ref_update *update = updates[i];
 		int flags = update->flags;
 
+		if (update->update_type != UPDATE_SHA1)
+			continue;
+
 		if (is_null_sha1(update->new_sha1))
 			flags |= REF_DELETING;
+
 		update->lock = lock_ref_sha1_basic(update->refname,
 						   (update->have_old ?
 						    update->old_sha1 :
@@ -3762,6 +3777,8 @@ int transaction_commit(struct transaction *transaction,
 	for (i = 0; i < n; i++) {
 		struct ref_update *update = updates[i];
 
+		if (update->update_type != UPDATE_SHA1)
+			continue;
 		if (!is_null_sha1(update->new_sha1)) {
 			if (write_ref_sha1(update->lock, update->new_sha1,
 					   update->msg)) {
@@ -3779,6 +3796,8 @@ int transaction_commit(struct transaction *transaction,
 	for (i = 0; i < n; i++) {
 		struct ref_update *update = updates[i];
 
+		if (update->update_type != UPDATE_SHA1)
+			continue;
 		if (update->lock) {
 			if (delete_ref_loose(update->lock, update->type, err)) {
 				ret = TRANSACTION_GENERIC_ERROR;
-- 
2.2.0.rc3