Bug#12340997 - DATE_ADD/DATE_SUB WITH INTERVAL CRASHES IN GET_INTERVAL_VALUE()

get_interval_value() was trying to parse the input string,
looking for leading '-' while skipping whitespace.
The macro my_isspace() does not work for utf16 character set,
since my_charset_utf16_general_ci.ctype == NULL.

Solution: convert input to ASCII before parsing.


mysql-test/r/ctype_utf16.result:
  New test case.
mysql-test/t/ctype_utf16.test:
  New test case.
sql/item_timefunc.cc:
  Use val_string_ascii() rather than val_string()
  so that we can safely use my_isspace() for skipping whitespace.

mysql-test/r/ctype_utf16.result

@@ -1117,5 +1117,14 @@ CASE s1 WHEN 'a' THEN 'b' ELSE 'c' END
 b
 DROP TABLE t1;
 #
+# Bug#12340997
+# DATE_ADD/DATE_SUB WITH INTERVAL CRASHES IN GET_INTERVAL_VALUE()
+#
+SELECT space(date_add(101, INTERVAL CHAR('1' USING utf16) hour_second));
+space(date_add(101, INTERVAL CHAR('1' USING utf16) hour_second))
+NULL
+Warnings:
+Warning	1301	Result of repeat() was larger than max_allowed_packet (1048576) - truncated
+#
 # End of 5.5 tests
 #

mysql-test/t/ctype_utf16.test

@@ -755,6 +755,13 @@ INSERT INTO t1 VALUES ('a');
 SELECT CASE s1 WHEN 'a' THEN 'b' ELSE 'c' END FROM t1;
 DROP TABLE t1;
 
+--echo #
+--echo # Bug#12340997
+--echo # DATE_ADD/DATE_SUB WITH INTERVAL CRASHES IN GET_INTERVAL_VALUE()
+--echo #
+
+SELECT space(date_add(101, INTERVAL CHAR('1' USING utf16) hour_second)); 
+
 #
 ## TODO: add tests for all engines
 #

sql/item_timefunc.cc

@@ -1430,7 +1430,7 @@ bool get_interval_value(Item *args,interval_type int_type,
   else
   {
     String *res;
-    if (!(res=args->val_str(str_value)))
+    if (!(res= args->val_str_ascii(str_value)))
       return (1);
 
     /* record negative intervalls in interval->neg */