Bug #21564557: INCONSISTENT OUTPUT FROM 5.5 AND 5.6

               UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%M"

Issue:
-----
When an invalid date is supplied to the UNIX_TIMESTAMP
function from STR_TO_DATE, no check is performed before
converting it to a timestamp value.

SOLUTION:
---------
Add the check_date function and only if it succeeds,
proceed to the timestamp conversion.

No warning will be returned for dates having zero in
month/date, since partial dates are allowed. UNIX_TIMESTAMP
will return only a zero for such values.

The problem has been handled in 5.6+ with WL#946.

mysql-test/r/func_time.result

@@ -1672,3 +1672,34 @@ insert into t1 values ('00:00:00'),('00:01:00');
 select 1 from t1 where 1 < some (select cast(a as datetime) from t1);
 1
 drop table t1;
+#
+# Bug #21564557: INCONSISTENT OUTPUT FROM 5.5 AND 5.6
+#                UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%M"
+#
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"));
+UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"))
+0
+SELECT UNIX_TIMESTAMP('2015-06-00');
+UNIX_TIMESTAMP('2015-06-00')
+0
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'));
+UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'))
+0
+set sql_mode= 'TRADITIONAL';
+SELECT @@sql_mode;
+@@sql_mode
+STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,TRADITIONAL,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"));
+UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"))
+NULL
+Warnings:
+Warning	1411	Incorrect datetime value: '201506' for function str_to_date
+SELECT UNIX_TIMESTAMP('2015-06-00');
+UNIX_TIMESTAMP('2015-06-00')
+0
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'));
+UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'))
+NULL
+Warnings:
+Warning	1411	Incorrect datetime value: '0000-00-00 10:30:30' for function str_to_date
+set sql_mode= default;

mysql-test/t/func_time.test

@@ -1026,3 +1026,21 @@ create table t1(a time);
 insert into t1 values ('00:00:00'),('00:01:00');
 select 1 from t1 where 1 < some (select cast(a as datetime) from t1);
 drop table t1;
+
+--echo #
+--echo # Bug #21564557: INCONSISTENT OUTPUT FROM 5.5 AND 5.6
+--echo #                UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%M"
+--echo #
+
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"));
+SELECT UNIX_TIMESTAMP('2015-06-00');
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'));
+
+set sql_mode= 'TRADITIONAL';
+SELECT @@sql_mode;
+
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('201506', "%Y%m"));
+SELECT UNIX_TIMESTAMP('2015-06-00');
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('0000-00-00 10:30:30', '%Y-%m-%d %h:%i:%s'));
+
+set sql_mode= default;

sql/item_timefunc.cc

 /*
-   Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -1378,7 +1378,7 @@ longlong Item_func_year::val_int_endpoint(bool left_endp, bool *incl_endp)
 longlong Item_func_unix_timestamp::val_int()
 {
   MYSQL_TIME ltime;
-  my_bool not_used;
+  my_bool not_used= 0;
   
   DBUG_ASSERT(fixed == 1);
   if (arg_count == 0)
@@ -1390,7 +1390,7 @@ longlong Item_func_unix_timestamp::val_int()
       return ((Field_timestamp*) field)->get_timestamp(&null_value);
   }
   
-  if (get_arg0_date(&ltime, 0))
+  if (get_arg0_date(&ltime, TIME_FUZZY_DATE))
   {
     /*
       We have to set null_value again because get_arg0_date will also set it
@@ -1400,7 +1400,11 @@ longlong Item_func_unix_timestamp::val_int()
     null_value= args[0]->null_value;
     return 0;
   }
-  
+
+  int dummy= 0;
+  if (check_date(&ltime, non_zero_date(&ltime), TIME_NO_ZERO_IN_DATE, &dummy))
+    return 0;
+
   return (longlong) TIME_to_timestamp(current_thd, &ltime, &not_used);
 }
 
@@ -3482,6 +3486,7 @@ bool Item_func_str_to_date::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
   String val_string(val_buff, sizeof(val_buff), &my_charset_bin), *val;
   String format_str(format_buff, sizeof(format_buff), &my_charset_bin), *format;
 
+  fuzzy_date|= sql_mode;
   val=    args[0]->val_str(&val_string);
   format= args[1]->val_str(&format_str);
   if (args[0]->null_value || args[1]->null_value)

sql/sql_time.h

-/* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -91,6 +91,11 @@ inline bool parse_date_time_format(timestamp_type format_type,
                                 date_time_format);
 }
 
+static inline bool
+non_zero_date(const MYSQL_TIME *ltime)
+{
+  return ltime->year || ltime->month || ltime->day;
+}
 
 extern DATE_TIME_FORMAT global_date_format;
 extern DATE_TIME_FORMAT global_datetime_format;