Commit d025029d authored by monty@hundin.mysql.fi's avatar monty@hundin.mysql.fi
Browse files

Fix for ISNULL()

parent d6fcf75a

Docs/manual.texi

+6 −1
Original line number Diff line number Diff line
@@ -46916,6 +46916,10 @@ not yet 100% confident in this code. 
@appendixsubsec Changes in release 3.23.51

@itemize @bullet

@item

Removed BDB documentation.

@item

Fixed mit-pthreads to compile with glibc 2.2 (needed for @code{make dist}).

@item

Fixed the @code{FLOAT(X+1,X)} is not converted to @code{FLOAT(X+2,X)}.

(This also affected @code{DECIMAL}, @code{DOUBLE} and @code{REAL} types)

@item
@@ -46929,7 +46933,8 @@ Fixed that underflowed decimal fields is not zero filled. 
If we get an overflow when inserting @code{'+11111'} for

@code{decimal(5,0) unsigned} columns, we will just drop the sign.

@item

Fixed bug with @code{ISNULL(expression_which_cannot_be_null)}.

Fixed optimization bug with @code{ISNULL(expression_which_cannot_be_null)} and

@code{ISNULL(constant_expression)}.

@item

Fixed host lookup bug in the glibc library that we used with the 3.23.50

Linux-x86 binaries.

mysql-test/r/join.result

+3 −0
Original line number Diff line number Diff line
@@ -27,6 +27,9 @@ d d 
0000-00-00	NULL

d

0000-00-00

d

2001-08-01

0000-00-00

COUNT(t1.Title)

1

COUNT(t1.Title)

mysql-test/t/join.test

+1 −0
Original line number Diff line number Diff line
@@ -120,6 +120,7 @@ CREATE TABLE t2 (d DATE NOT NULL); 
INSERT INTO t1 (d) VALUES ('2001-08-01'),('0000-00-00');

SELECT * FROM t1 LEFT JOIN t2 USING (d) WHERE t2.d IS NULL;

SELECT * from t1 WHERE t1.d IS NULL;

SELECT * FROM t1 WHERE 1/0 IS NULL;

DROP TABLE t1,t2;



#

sql/item_cmpfunc.cc

+1 −1
Original line number Diff line number Diff line
@@ -1211,7 +1211,7 @@ longlong Item_func_isnull::val_int() 
    This has to be here because of the test in update_used_tables().

  */

  if (!used_tables_cache)

    return 0;

    return cached_value;

  (void) args[0]->val();

  return (args[0]->null_value) ? 1 : 0;

}

sql/item_cmpfunc.h

+7 −0
Original line number Diff line number Diff line
@@ -429,6 +429,7 @@ class Item_func_in :public Item_int_func 


class Item_func_isnull :public Item_bool_func

{

  longlong cached_value;

public:

  Item_func_isnull(Item *a) :Item_bool_func(a) {}

  longlong val_int();
@@ -449,6 +450,12 @@ class Item_func_isnull :public Item_bool_func 
      args[0]->update_used_tables();

      used_tables_cache=args[0]->used_tables();

    }

    if (!used_tables_cache)

    {

      /* Remember if the value is always NULL or never NULL */

      args[0]->val();

      cached_value= args[0]->null_value ? (longlong) 1 : (longlong) 0;

    }

  }

  optimize_type select_optimize() const { return OPTIMIZE_NULL; }

};