From 4faa9da81c00725dfe8c36e01cf15414918eb1f3 Mon Sep 17 00:00:00 2001
From: Sergei Petrunia <psergey@askmonty.org>
Date: Tue, 27 Dec 2016 01:55:05 +0300
Subject: [PATCH] MariaRocks port: Make SQL layer allow errors in
 start_consistent_snapshot().

rocksdb.cons_snapshot_read_committed test used to crash.
This happened, because
- MyRocks produces an error when one attempts to do a START TRANSACTION
  WITH CONSISTENT SNAPSHOT with @@tx_isolation=REPEATABLE_READ
- MariaDB's SQL layer didn't assume that errors are possible inside
  hton->start_constistent_snapshot() call.
---
 sql/sql_parse.cc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index ac00b21c837..e415b275fff 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -5428,7 +5428,9 @@ end_with_restore_list:
                   (longlong) thd->thread_id);
       goto error;
     }
-    my_ok(thd);
+    /* MyRocks: hton->start_consistent_snapshot call may fail with an error */
+    if (!thd->is_error())
+      my_ok(thd);
     break;
   case SQLCOM_COMMIT:
   {