Bug#48525: trigger changes "Column 'id' cannot be null" behaviour

CHECK_FIELD_IGNORE was treated as CHECK_FIELD_ERROR_FOR_NULL;
UPDATE...SET...NULL on NOT NULL fields behaved differently after
a trigger.

Now distinguishes between IGNORE and ERROR_FOR_NULL and save/restores
check-field options.

mysql-test/r/trigger.result:
  Show that UPDATE...SET...NULL on NOT NULL columns doesn't behave differently
  when run after a trigger.
mysql-test/t/trigger.test:
  Show that UPDATE...SET...NULL on NOT NULL columns doesn't behave differently
  when run after a trigger.
sql/field_conv.cc:
  CHECK_FIELD_IGNORE was treated as CHECK_FIELD_ERROR_FOR_NULL.
  Distinguish between the two.
sql/sp_head.cc:
  raise error as needed
sql/sql_class.cc:
  Save and restore check-fields options.
sql/sql_class.h:
  Make room so we can save check-fields options.
sql/sql_insert.cc:
  raise error as needed

1 files changed, 1 insertions, 1 deletions

diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index 1f4ca90157f..35c24e7571e 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -3158,7 +3158,7 @@ bool select_insert::send_data(List<Item> &values)
 
   thd->count_cuted_fields= CHECK_FIELD_WARN;	// Calculate cuted fields
   store_values(values);
-  thd->count_cuted_fields= CHECK_FIELD_IGNORE;
+  thd->count_cuted_fields= CHECK_FIELD_ERROR_FOR_NULL;
   if (thd->is_error())
   {
     table->auto_increment_field_not_null= FALSE;