Bug #20195: INSERT DELAYED with auto_increment is assigned wrong values

The INSERT DELAYED should not maintain its own private auto-increment
counter, because this is assuming that other threads cannot insert
into the table while the INSERT DELAYED thread is inserting, which is
a wrong assumption.

So the start of processing of a batch of INSERT rows in the 
INSERT DELAYED thread must be treated as a start of a new statement
and cached next_insert_id must be cleared.


mysql-test/r/delayed.result:
  test suite for the bug
mysql-test/t/delayed.test:
  test suite for the bug
sql/sql_insert.cc:
  Reset auto-increment cacheing before processing
  the next batch of inserts in the handler thread

1 files changed, 8 insertions, 0 deletions

diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index 26f3b6f5faa..5630702fe52 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -1938,6 +1938,14 @@ bool delayed_insert::handle_inserts(void)
   if (!using_bin_log)
     table->file->extra(HA_EXTRA_WRITE_CACHE);
   pthread_mutex_lock(&mutex);
+
+  /* Reset auto-increment cacheing */
+  if (thd.clear_next_insert_id)
+  {
+    thd.next_insert_id= 0;
+    thd.clear_next_insert_id= 0;
+  }
+
   while ((row=rows.get()))
   {
     stacked_inserts--;