[PATCH v7 09/42] refs.c: change ref_transaction_create to do error checking and return status

[Ronnie Sahlberg <sahlberg@google.com>]

Do basic error checking in ref_transaction_create() and make it return
non-zero on error. Update all callers to check the result of
ref_transaction_create(). There are currently no conditions in _create that
will return error but there will be in the future.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 builtin/update-ref.c |  4 +++-
 refs.c               | 17 +++++++++++------
 refs.h               |  9 +++++----
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 59c4d6b..3fab810 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -225,7 +225,9 @@ static const char *parse_cmd_create(struct strbuf *input, const char *next)
 	if (*next != line_termination)
 		die("create %s: extra input: %s", refname, next);
 
-	ref_transaction_create(transaction, refname, new_sha1, update_flags);
+	if (ref_transaction_create(transaction, refname, new_sha1,
+				   update_flags))
+		die("failed transaction create for %s", refname);
 
 	update_flags = 0;
 	free(refname);
diff --git a/refs.c b/refs.c
index 77b27ce..df376fa 100644
--- a/refs.c
+++ b/refs.c
@@ -3362,18 +3362,23 @@ int ref_transaction_update(struct ref_transaction *transaction,
 	return 0;
 }
 
-void ref_transaction_create(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    int flags)
+int ref_transaction_create(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   int flags)
 {
-	struct ref_update *update = add_update(transaction, refname);
+	struct ref_update *update;
+
+	if (!new_sha1 || is_null_sha1(new_sha1))
+		die("create ref with null new_sha1");
+
+	update = add_update(transaction, refname);
 
-	assert(!is_null_sha1(new_sha1));
 	hashcpy(update->new_sha1, new_sha1);
 	hashclr(update->old_sha1);
 	update->flags = flags;
 	update->have_old = 1;
+	return 0;
 }
 
 void ref_transaction_delete(struct ref_transaction *transaction,
diff --git a/refs.h b/refs.h
index 57103aa..d4c068d 100644
--- a/refs.h
+++ b/refs.h
@@ -255,11 +255,12 @@ int ref_transaction_update(struct ref_transaction *transaction,
  * that the reference should have after the update; it must not be the
  * null SHA-1.  It is verified that the reference does not exist
  * already.
+ * Function returns 0 on success and non-zero on failure.
  */
-void ref_transaction_create(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    int flags);
+int ref_transaction_create(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   int flags);
 
 /*
  * Add a reference deletion to transaction.  If have_old is true, then
-- 
2.0.0.rc3.471.g2055d11.dirty