A fix (bug #10568: Function 'LAST_DAY(date)' does not return NULL for invalid argument).

sql/item_timefunc.cc:
  A fix (bug #10568: Function 'LAST_DAY(date)' does not return NULL for invalid argument).
  Return error for partial dates as well.

mysql-test/r/func_time.result

@@ -688,3 +688,18 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1003	select timestamp_diff(WEEK,_latin1'2001-02-01',_latin1'2001-05-01') AS `a1`,timestamp_diff(SECOND_FRAC,_latin1'2001-02-01 12:59:59.120000',_latin1'2001-05-01 12:58:58.119999') AS `a2`
+select last_day('2005-00-00');
+last_day('2005-00-00')
+NULL
+Warnings:
+Warning	1292	Truncated incorrect datetime value: '2005-00-00'
+select last_day('2005-00-01');
+last_day('2005-00-01')
+NULL
+Warnings:
+Warning	1292	Truncated incorrect datetime value: '2005-00-01'
+select last_day('2005-01-00');
+last_day('2005-01-00')
+NULL
+Warnings:
+Warning	1292	Truncated incorrect datetime value: '2005-01-00'

mysql-test/t/func_time.test

@@ -336,3 +336,11 @@ DROP TABLE t1;
 
 explain extended select timestampdiff(SQL_TSI_WEEK, '2001-02-01', '2001-05-01') as a1,
 			timestampdiff(SQL_TSI_FRAC_SECOND, '2001-02-01 12:59:59.120000', '2001-05-01 12:58:58.119999') as a2;
+
+#
+# Bug #10568
+#
+
+select last_day('2005-00-00');
+select last_day('2005-00-01');
+select last_day('2005-01-00');

sql/item_timefunc.cc

@@ -3015,7 +3015,7 @@ String *Item_func_str_to_date::val_str(String *str)
 
 bool Item_func_last_day::get_date(TIME *ltime, uint fuzzy_date)
 {
-  if (get_arg0_date(ltime,fuzzy_date))
+  if (get_arg0_date(ltime, fuzzy_date & ~TIME_FUZZY_DATE))
     return 1;
   uint month_idx= ltime->month-1;
   ltime->day= days_in_month[month_idx];