Bug#44653: Server crash noticed when executing random queries with partitions.

When opening a table, it is imperative that the flag
TABLE::auto_increment_field_not_null be false. But if an error occured during
the creation of a table (e.g. the table exists already) with an auto_increment
column and a BEFORE trigger that used the INSERT ... SELECT construct, the
flag was not reset until after error checking. Thus if an error occured,
select_insert::send_data() returned immediately and it was not reset (see * in
pseudocode below).  Crash happened if the table was opened again. Fixed by
resetting the flag after error checking.

nested-loops_join():
  for each row in SELECT table {
    select_insert::send_data():
      if a values is supplied for AUTO_INCREMENT column
         table->auto_increment_field_not_null= TRUE
       else
         table->auto_increment_field_not_null= FALSE
       if (error)
         return 1; *
       if (table->auto_increment_field_not_null == FALSE)
         ...
       table->auto_increment_field_not_null == FALSE 
  }
<-- table returned to table cache and later retrieved by open_table: 
open_table():
  assert(table->auto_increment_field_not_null)


mysql-test/r/trigger.result:
  Bug#44653: Test result
mysql-test/t/trigger.test:
  Bug#44653: Test case
sql/sql_insert.cc:
  Bug#44653: Fix: Make sure to unset this field before returning in case of error

mysql-test/r/trigger.result

@@ -2073,4 +2073,18 @@ select @a, @b;
 drop trigger trg1;
 drop trigger trg2;
 drop table t1, t2;
+CREATE TABLE t1 ( a INT, b INT );
+CREATE TABLE t2 ( a INT AUTO_INCREMENT KEY, b INT );
+INSERT INTO t1 (a) VALUES (1);
+CREATE TRIGGER tr1
+BEFORE INSERT ON t2
+FOR EACH ROW 
+BEGIN 
+UPDATE a_nonextisting_table SET a = 1;
+END//
+CREATE TABLE IF NOT EXISTS t2 ( a INT, b INT ) SELECT a, b FROM t1;
+ERROR 42S02: Table 'test.a_nonextisting_table' doesn't exist
+SELECT * FROM t2;
+a	b
+DROP TABLE t1, t2;
 End of 5.1 tests.

mysql-test/t/trigger.test

@@ -2370,4 +2370,30 @@ drop trigger trg1;
 drop trigger trg2;
 drop table t1, t2;
 
+#
+# Bug#44653: Server crash noticed when executing random queries with partitions.
+#
+CREATE TABLE t1 ( a INT, b INT );
+CREATE TABLE t2 ( a INT AUTO_INCREMENT KEY, b INT );
+
+INSERT INTO t1 (a) VALUES (1);
+
+delimiter //;
+CREATE TRIGGER tr1
+BEFORE INSERT ON t2
+FOR EACH ROW 
+BEGIN 
+  UPDATE a_nonextisting_table SET a = 1;
+END//
+delimiter ;//
+
+--disable_abort_on_error
+CREATE TABLE IF NOT EXISTS t2 ( a INT, b INT ) SELECT a, b FROM t1;
+--enable_abort_on_error
+
+# Caused failed assertion
+SELECT * FROM t2;
+
+DROP TABLE t1, t2;
+
 --echo End of 5.1 tests.

sql/sql_insert.cc

@@ -3100,7 +3100,10 @@ bool select_insert::send_data(List<Item> &values)
   store_values(values);
   thd->count_cuted_fields= CHECK_FIELD_IGNORE;
   if (thd->is_error())
+  {
+    table->auto_increment_field_not_null= FALSE;
     DBUG_RETURN(1);
+  }
   if (table_list)                               // Not CREATE ... SELECT
   {
     switch (table_list->view_check_option(thd, info.ignore)) {