Patrick Steinhardt [off-list ref] writes:

On Sat, Sep 13, 2025 at 10:54:30PM +0200, Karthik Nayak wrote:

quoted

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 01df32904b..69e50a16db 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c

@@ -797,9 +797,23 @@ static enum ref_transaction_error lock_raw_ref(struct files_ref_store *refs,
 			goto retry;
 		} else {
 			unable_to_lock_message(ref_file.buf, myerr, err);
-			if (myerr == EEXIST && ignore_case &&
-			    transaction_has_case_conflicting_update(transaction, update))
-				ret = REF_TRANSACTION_ERROR_CASE_CONFLICT;
+			if (myerr == EEXIST) {
+				if (ignore_case &&
+				    transaction_has_case_conflicting_update(transaction, update))
+					/*
+					 * In case-insensitive filesystems, ensure that conflicts within a
+					 * given transaction are handled. Pre-existing refs on a
+					 * case-insensitive system will be overridden without any issue.
+					 */
+					ret = REF_TRANSACTION_ERROR_CASE_CONFLICT;
+				else
+					/*
+					 * Pre-existing case-conflicting reference locks should also be
+					 * specially categorized to avoid failing all batched updates.
+					 */
+					ret = REF_TRANSACTION_ERROR_CREATE_EXISTS;
+			}

Tiniest nit: I think it would be preferable to use curly braces for such
multi-line comments. This nit isn't worth a reroll though.

I did contemplate about this in my mind, thanks for raising this. I will
change it locally for now and push a new version if needed.

Other than that my feedback got addressed, so this looks good to me.
Thanks!

Patrick

Thanks for your reviews!