Fix for bug #23412: delete rows with null date field

Backport of the fix for bug #8143: A date with value 0 is treated as a NULL value


mysql-test/r/delete.result:
  Fix for bug #23412: delete rows with null date field
    - test result
mysql-test/t/delete.test:
  Fix for bug #23412: delete rows with null date field
    - test case
sql/sql_delete.cc:
  Fix for bug #23412: delete rows with null date field
    - during SELECT queries processing we convert 'date[time]_field is null'                   
      conditions into 'date[time]_field = 0000-00-00[ 00:00:00]' for not null                  
      DATE and DATETIME fields. To be consistent, we have to do the same for DELETE            
      queries. So we should call remove_eq_conds() in the mysql_delete() as well.              
      Also it may simplify and speed up DELETE queries execution.

1 files changed, 12 insertions, 1 deletions

diff --git a/mysql-test/t/delete.test b/mysql-test/t/delete.test
index d4eb01cab23..2036b59d810 100644
--- a/mysql-test/t/delete.test
+++ b/mysql-test/t/delete.test
@@ -163,4 +163,15 @@ delete `4.t1` from t1 as `4.t1` where `4.t1`.a = 5;
 delete FROM `4.t1` USING t1 as `4.t1` where `4.t1`.a = 5;
 drop table t1;
 
-# End of 4.1 tests
+#
+# Bug #8143: deleting '0000-00-00' values using IS NULL
+#
+
+create table t1(a date not null); 
+insert into t1 values (0); 
+select * from t1 where a is null; 
+delete from t1 where a is null; 
+select count(*) from t1; 
+drop table t1; 
+
+--echo End of 4.1 tests