Fixed that NULL and 0 returns 0 instead of NULL

This is coded to not cause a speed impact on top level AND expressions where we don't care if an AND expression returns 0 or NULL


mysql-test/r/bdb.result:
  Fix results after serges last patch
mysql-test/r/innodb.result:
  Fix results after serges last patch
mysql-test/r/null.result:
  Update for new AND handling of NULL
scripts/mysqld_safe.sh:
  Fix 'isroot' test to work even if user is not root
sql/item.h:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/item_cmpfunc.cc:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/item_cmpfunc.h:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/sql_base.cc:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/sql_parse.cc:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/sql_select.cc:
  Fixed that NULL and 0 returns 0 instead of NULL
sql/sql_yacc.yy:
  Fixed that NULL and 0 returns 0 instead of NULL

1 files changed, 28 insertions, 0 deletions

diff --git a/mysql-test/t/bool.test b/mysql-test/t/bool.test
new file mode 100644
index 00000000000..5754acf4bcd
--- /dev/null
+++ b/mysql-test/t/bool.test
@@ -0,0 +1,28 @@
+#
+# Test of boolean operations with NULL
+#
+
+DROP TABLE IF EXISTS t1;
+
+SELECT IF(NULL AND 1, 1, 2), IF(1 AND NULL, 1, 2);
+SELECT NULL AND 1, 1 AND NULL, 0 AND NULL, NULL and 0;
+
+create table t1 (a int);
+insert into t1 values (0),(1),(NULL);
+SELECT * FROM t1 WHERE IF(a AND 1, 0, 1);
+SELECT * FROM t1 WHERE IF(1 AND a, 0, 1);
+SELECT * FROM t1 where NOT(a AND 1);
+SELECT * FROM t1 where NOT(1 AND a);
+SELECT * FROM t1 where (a AND 1)=0;
+SELECT * FROM t1 where (1 AND a)=0;
+SELECT * FROM t1 where (1 AND a)=1;
+SELECT * FROM t1 where (1 AND a) IS NULL;
+
+# Verify that NULL optimisation works in AND clause:
+SET @a=0, @b=0;
+SELECT * FROM t1 WHERE NULL AND (@a:=@a+1);
+SELECT * FROM t1 WHERE NOT(a>=0 AND NULL AND (@b:=@b+1));
+SELECT * FROM t1 WHERE a=2 OR (NULL AND (@a:=@a+1));
+SELECT * FROM t1 WHERE NOT(a=2 OR (NULL AND (@b:=@b+1)));
+SELECT @a, @b;
+DROP TABLE t1;