Bug#45263 utf32_general_ci, bad effects around CREATE TABLE AS SELECT

Problem: Item_func_hex::val_str() returned data in ASCII format,
which did not match collation.collation pointing to my_charset_utf32_general_ci.
Fix: changing parent class of Item_func_hex to Item_str_ascii_func,
as val_str() implementation is heavily ASCII-oriented.

  mysql-test/r/ctype_utf32.result
  mysql-test/t/ctype_utf32.test
  Adding test case


  sql/item_strfunc.cc
  sql/item_strfunc.h
  - Changing parent class to Item_str_ascii_func
  - Clean-up in Item_func_hex::fix_length_and_dec()
    Using fix_char_length() instead of setting max_length directly.

1 files changed, 4 insertions, 4 deletions

diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index df794ecaaf4..4461373f7b3 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -622,18 +622,18 @@ public:
 };
 
 
-class Item_func_hex :public Item_str_func
+class Item_func_hex :public Item_str_ascii_func
 {
   String tmp_value;
 public:
-  Item_func_hex(Item *a) :Item_str_func(a) {}
+  Item_func_hex(Item *a) :Item_str_ascii_func(a) {}
   const char *func_name() const { return "hex"; }
-  String *val_str(String *);
+  String *val_str_ascii(String *);
   void fix_length_and_dec()
   {
     collation.set(default_charset());
     decimals=0;
-    max_length=args[0]->max_length*2*collation.collation->mbmaxlen;
+    fix_char_length(args[0]->max_length * 2);
   }
 };