[PATCH 5/8] refs.c: add transaction function to delete the reflog

From

Stefan Beller <sbeller@google.com>

Date

Dec 6, 2014, 02:46 UTC

Message-ID

<1417833995-25687-6-git-send-email-sbeller@google.com>

In-Reply-To

<1417833995-25687-1-git-send-email-sbeller@google.com>

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 refs.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 1 deletion(-)

diff --git a/refs.c b/refs.c
index d767418..57f4941 100644
--- a/refs.c
+++ b/refs.c
@@ -3649,6 +3649,56 @@ int transaction_update_ref(struct transaction *transaction,
 }
 
 /*
+ * Delete the reflog for the given refname.
+ *
+ */
+static int transaction_delete_reflog(struct transaction *transaction,
+				       const char *refname,
+				       struct strbuf *err)
+{
+	struct lock_file *lock;
+	struct string_list_item *item;
+
+	if (transaction->state != TRANSACTION_OPEN)
+		die("BUG: delete_reflog called for transaction that is not open");
+
+	item = string_list_insert(&transaction->reflog_updates, refname);
+
+	if (!item->util) {
+		char *path = git_path("logs/locks/%s", refname);
+		lock = xcalloc(1, sizeof(struct lock_file));
+		item->util = lock;
+		if (safe_create_leading_directories(path)) {
+			strbuf_addf(err, "could not create leading directories of '%s': %s",
+				    path, strerror(errno));
+			goto failure;
+		}
+
+		if (hold_lock_file_for_update(lock, path, 0) < 0) {
+			unable_to_lock_message(path, errno, err);
+			goto failure;
+		}
+		/* The empty file indicates transaction_commit to
+		 * delete the reflog */
+		return 0;
+	}
+
+	/* The transaction already writes to this reflog.  Clear it. */
+	lock = item->util;
+	if (lseek(lock->fd, 0, SEEK_SET) < 0 ||
+	    ftruncate(lock->fd, 0)) {
+		strbuf_addf(err, "cannot truncate reflog '%s': %s",
+			    refname, strerror(errno));
+		goto failure;
+	}
+	return 0;
+
+failure:
+	transaction->state = TRANSACTION_CLOSED;
+	return -1;
+}
+
+/*
  * Append a reflog entry for refname.
  */
 static int transaction_update_reflog(struct transaction *transaction,
@@ -3885,7 +3935,17 @@ int transaction_commit(struct transaction *transaction,
 	/* Commit all reflog updates*/
 	for_each_string_list_item(item, &transaction->reflog_updates) {
 		struct lock_file *lock = item->util;
-		commit_lock_file_to(lock, git_path("logs/%s", item->string));
+
+		/* If the lock file is empty we want to delete the reflog*/
+		off_t filepos = lseek(lock->fd, 0, SEEK_END);
+		if (filepos < 0) {
+			ret = TRANSACTION_GENERIC_ERROR;
+			goto cleanup;
+		}
+		if (filepos)
+			commit_lock_file_to(lock, git_path("logs/%s", item->string));
+		else
+			remove_path(git_path("logs/%s", item->string));
 	}
 
 	clear_loose_ref_cache(&ref_cache);

-- 
2.2.0