From 7c63b5cbb480f05fdf9648ef4ff26669ae2fc004 Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Wed, 27 May 2020 17:53:10 +0100
Subject: [PATCH] Handle nil in transaction

---
 roomserver/storage/shared/prepare.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/roomserver/storage/shared/prepare.go b/roomserver/storage/shared/prepare.go
index e048d43af..65ceec1cc 100644
--- a/roomserver/storage/shared/prepare.go
+++ b/roomserver/storage/shared/prepare.go
@@ -43,10 +43,18 @@ type transaction struct {
 
 // Commit implements types.Transaction
 func (t *transaction) Commit() error {
+	if t.txn == nil {
+		// The Updater structs can operate in useTxns=false mode. The code will still call this though.
+		return nil
+	}
 	return t.txn.Commit()
 }
 
 // Rollback implements types.Transaction
 func (t *transaction) Rollback() error {
+	if t.txn == nil {
+		// The Updater structs can operate in useTxns=false mode. The code will still call this though.
+		return nil
+	}
 	return t.txn.Rollback()
 }