From 1c04310e30b77d8dc7cae66fa5ea9b263faca92f Mon Sep 17 00:00:00 2001
From: "ramil/ram@mysql.com/myoffice.izhnet.ru" <>
Date: Sun, 23 Jul 2006 15:25:30 +0500
Subject: [PATCH] Fix for bug #8143: A date with value 0 is treated as a NULL
 value

---
 mysql-test/r/delete.result | 10 ++++++++++
 mysql-test/t/delete.test   | 11 +++++++++++
 sql/sql_delete.cc          |  8 ++++++++
 3 files changed, 29 insertions(+)

diff --git a/mysql-test/r/delete.result b/mysql-test/r/delete.result
index 05f1c967e77..0946dc8f809 100644
--- a/mysql-test/r/delete.result
+++ b/mysql-test/r/delete.result
@@ -192,3 +192,13 @@ delete t2.*,t3.* from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
 select * from t3;
 a	b
 drop table t1,t2,t3;
+create table t1(a date not null);
+insert into t1 values (0);
+select * from t1 where a is null;
+a
+0000-00-00
+delete from t1 where a is null;
+select count(*) from t1;
+count(*)
+0
+drop table t1;
diff --git a/mysql-test/t/delete.test b/mysql-test/t/delete.test
index 4284bd2a06d..677ffaa2860 100644
--- a/mysql-test/t/delete.test
+++ b/mysql-test/t/delete.test
@@ -171,3 +171,14 @@ delete t2.*,t3.* from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
 # This should be empty
 select * from t3;
 drop table t1,t2,t3;
+
+#
+# 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;
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index 381d1a71e31..b608773bf6e 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -91,6 +91,14 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     /* Handler didn't support fast delete; Delete rows one by one */
   }
 
+  if (conds)
+  {
+    Item::cond_result result;
+    conds= remove_eq_conds(thd, conds, &result);
+    if (result == Item::COND_FALSE)             // Impossible where
+      limit= 0;
+  }
+
   table->used_keys.clear_all();
   table->quick_keys.clear_all();		// Can't use 'only index'
   select=make_select(table, 0, 0, conds, 0, &error);