Bug#11766124 59164: VALGRIND: UNINITIALIZED VALUE IN NUMBER_TO_DATETIME

Valgrind warning happens due to missing NULL value check in
Item::get_date. The fix is to add this check.

mysql-test/r/func_time.result

@@ -1399,4 +1399,10 @@ NULL
 SELECT CAST((MONTH(FROM_UNIXTIME(@@GLOBAL.SQL_MODE))) AS BINARY(1025));
 CAST((MONTH(FROM_UNIXTIME(@@GLOBAL.SQL_MODE))) AS BINARY(1025))
 NULL
+#
+# Bug#11766124  59164: VALGRIND: UNINITIALIZED VALUE IN NUMBER_TO_DATETIME
+#
+SELECT ADDDATE(MONTH(FROM_UNIXTIME(NULL)),INTERVAL 1 HOUR);
+ADDDATE(MONTH(FROM_UNIXTIME(NULL)),INTERVAL 1 HOUR)
+NULL
 End of 5.1 tests

mysql-test/t/func_time.test

@@ -907,4 +907,10 @@ SELECT FORMAT(YEAR(STR_TO_DATE('',GET_FORMAT(TIME,''))),1);
 
 SELECT CAST((MONTH(FROM_UNIXTIME(@@GLOBAL.SQL_MODE))) AS BINARY(1025));
 
+--echo #
+--echo # Bug#11766124  59164: VALGRIND: UNINITIALIZED VALUE IN NUMBER_TO_DATETIME
+--echo #
+
+SELECT ADDDATE(MONTH(FROM_UNIXTIME(NULL)),INTERVAL 1 HOUR);
+
 --echo End of 5.1 tests

sql/item.cc

@@ -926,8 +926,12 @@ bool Item::get_date(MYSQL_TIME *ltime,uint fuzzydate)
   }
   else
   {
-    longlong value= val_int();
     int was_cut;
+    longlong value= val_int();
+
+    if (null_value)
+      goto err;
+
     if (number_to_datetime(value, ltime, fuzzydate, &was_cut) == LL(-1))
     {
       char buff[22], *end;