MDEV-4635 Crash in UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))

modified:
  mysql-test/r/func_time.result
  mysql-test/t/func_time.test
  sql/item_timefunc.cc
  sql/mysql_priv.h

mysql-test/r/func_time.result

@@ -1910,3 +1910,13 @@ SELECT 1 FROM DUAL WHERE MINUTE(TIMEDIFF(NULL, '12:12:12'));
 1
 SELECT 1 FROM DUAL WHERE SECOND(TIMEDIFF(NULL, '12:12:12'));
 1
+#
+# MDEV-4635 Crash in UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))
+#
+SET TIME_ZONE='+02:00';
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'));
+UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))
+NULL
+Warnings:
+Error	1411	Incorrect datetime value: '2020' for function str_to_date
+SET TIME_ZONE=DEFAULT;

mysql-test/t/func_time.test

@@ -1154,3 +1154,11 @@ SELECT 1 FROM DUAL WHERE DAYOFMONTH(TIMEDIFF(NULL, '12:12:12'));
 SELECT 1 FROM DUAL WHERE HOUR(TIMEDIFF(NULL, '12:12:12'));
 SELECT 1 FROM DUAL WHERE MINUTE(TIMEDIFF(NULL, '12:12:12'));
 SELECT 1 FROM DUAL WHERE SECOND(TIMEDIFF(NULL, '12:12:12'));
+
+
+--echo #
+--echo # MDEV-4635 Crash in UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'))
+--echo #
+SET TIME_ZONE='+02:00';
+SELECT UNIX_TIMESTAMP(STR_TO_DATE('2020','%Y'));
+SET TIME_ZONE=DEFAULT;

sql/item_timefunc.cc

@@ -396,8 +396,8 @@ static bool extract_date_time(DATE_TIME_FORMAT *format,
       l_time->minute > 59 || l_time->second > 59)
     goto err;
 
-  if ((fuzzy_date & TIME_NO_ZERO_DATE) &&
-       (l_time->year == 0 || l_time->month == 0 || l_time->day == 0))
+  int was_cut;
+  if (check_date(l_time, fuzzy_date | TIME_INVALID_DATES, &was_cut))
     goto err;
 
   if (val != val_end)
@@ -799,7 +799,6 @@ longlong Item_func_to_days::val_int_endpoint(bool left_endp, bool *incl_endp)
   res=(longlong) calc_daynr(ltime.year,ltime.month,ltime.day);
   /* Set to NULL if invalid date, but keep the value */
   null_value= check_date(&ltime,
-                         (ltime.year || ltime.month || ltime.day),
                          (TIME_NO_ZERO_IN_DATE | TIME_NO_ZERO_DATE),
                          &dummy);
   if (null_value)
@@ -1126,7 +1125,7 @@ bool Item_func_unix_timestamp::get_timestamp_value(my_time_t *seconds,
   }
 
   MYSQL_TIME ltime;
-  if (get_arg0_date(&ltime, 0))
+  if (get_arg0_date(&ltime, TIME_NO_ZERO_IN_DATE))
     return 1;
 
   uint error_code;
@@ -2309,8 +2308,7 @@ bool Item_date_typecast::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
   ltime->time_type= MYSQL_TIMESTAMP_DATE;
 
   int unused;
-  if (check_date(ltime, ltime->year || ltime->month || ltime->day,
-                 fuzzy_date, &unused))
+  if (check_date(ltime, fuzzy_date, &unused))
   {
     Lazy_string_time str(ltime);
     make_truncated_value_warning(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,

sql/mysql_priv.h

@@ -2558,7 +2558,16 @@ extern bool make_date_time(DATE_TIME_FORMAT *format, MYSQL_TIME *l_time,
 int my_time_compare(MYSQL_TIME *a, MYSQL_TIME *b);
 longlong get_datetime_value(THD *thd, Item ***item_arg, Item **cache_arg,
                             Item *warn_item, bool *is_null);
-
+static inline bool
+non_zero_date(const MYSQL_TIME *ltime)
+{
+  return ltime->year || ltime->month || ltime->day;
+}
+static inline bool
+check_date(const MYSQL_TIME *ltime, ulonglong flags, int *was_cut)
+{
+  return check_date(ltime, non_zero_date(ltime), flags, was_cut);
+}
 int test_if_number(char *str,int *res,bool allow_wildcards);
 void change_byte(uchar *,uint,char,char);
 bool init_read_record(READ_RECORD *info, THD *thd, TABLE *reg_form,