1 files changed, 62 insertions, 46 deletions

diff --git a/sql/item.cc b/sql/item.cc
index f74d8df1045..35a88d10fe0 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -1272,13 +1272,26 @@ Item::Type Item_name_const::type() const
     valid_args guarantees value_item->basic_const_item(); if type is
     FUNC_ITEM, then we have a fudged item_func_neg() on our hands
     and return the underlying type.
+    For Item_func_set_collation()
+    e.g. NAME_CONST('name', 'value' COLLATE collation) we return its
+    'value' argument type. 
   */
-  return valid_args ?
-             (((value_item->type() == FUNC_ITEM) &&
-               (((Item_func *) value_item)->functype() == Item_func::NEG_FUNC)) ?
-             ((Item_func *) value_item)->key_item()->type() :
-             value_item->type()) :
-           NULL_ITEM;
+  if (!valid_args)
+    return NULL_ITEM;
+  Item::Type value_type= value_item->type();
+  if (value_type == FUNC_ITEM)
+  {
+    /* 
+      The second argument of NAME_CONST('name', 'value') must be 
+      a simple constant item or a NEG_FUNC/COLLATE_FUNC.
+    */
+    DBUG_ASSERT(((Item_func *) value_item)->functype() == 
+                Item_func::NEG_FUNC ||
+                ((Item_func *) value_item)->functype() == 
+                Item_func::COLLATE_FUNC);
+    return ((Item_func *) value_item)->key_item()->type();            
+  }
+  return value_type;
 }
 
 
@@ -1624,48 +1637,11 @@ bool agg_item_collations_for_comparison(DTCollation &c, const char *fname,
 }
 
 
-/**
-  Collect arguments' character sets together.
-
-  We allow to apply automatic character set conversion in some cases.
-  The conditions when conversion is possible are:
-  - arguments A and B have different charsets
-  - A wins according to coercibility rules
-    (i.e. a column is stronger than a string constant,
-     an explicit COLLATE clause is stronger than a column)
-  - character set of A is either superset for character set of B,
-    or B is a string constant which can be converted into the
-    character set of A without data loss.
-    
-  If all of the above is true, then it's possible to convert
-  B into the character set of A, and then compare according
-  to the collation of A.
-  
-  For functions with more than two arguments:
-  @code
-    collect(A,B,C) ::= collect(collect(A,B),C)
-  @endcode
-  Since this function calls THD::change_item_tree() on the passed Item **
-  pointers, it is necessary to pass the original Item **'s, not copies.
-  Otherwise their values will not be properly restored (see BUG#20769).
-  If the items are not consecutive (eg. args[2] and args[5]), use the
-  item_sep argument, ie.
-  @code
-    agg_item_charsets(coll, fname, &args[2], 2, flags, 3)
-  @endcode
-*/
-
-bool agg_item_charsets(DTCollation &coll, const char *fname,
-                       Item **args, uint nargs, uint flags, int item_sep)
+bool agg_item_set_converter(DTCollation &coll, const char *fname,
+                            Item **args, uint nargs, uint flags, int item_sep)
 {
   Item **arg, *safe_args[2];
 
-  LINT_INIT(safe_args[0]);
-  LINT_INIT(safe_args[1]);
-
-  if (agg_item_collations(coll, fname, args, nargs, flags, item_sep))
-    return TRUE;
-
   /*
     For better error reporting: save the first and the second argument.
     We need this only if the the number of args is 3 or 2:
@@ -1745,6 +1721,46 @@ bool agg_item_charsets(DTCollation &coll, const char *fname,
 }
 
 
+/* 
+  Collect arguments' character sets together.
+  We allow to apply automatic character set conversion in some cases.
+  The conditions when conversion is possible are:
+  - arguments A and B have different charsets
+  - A wins according to coercibility rules
+    (i.e. a column is stronger than a string constant,
+     an explicit COLLATE clause is stronger than a column)
+  - character set of A is either superset for character set of B,
+    or B is a string constant which can be converted into the
+    character set of A without data loss.
+    
+  If all of the above is true, then it's possible to convert
+  B into the character set of A, and then compare according
+  to the collation of A.
+  
+  For functions with more than two arguments:
+
+    collect(A,B,C) ::= collect(collect(A,B),C)
+
+  Since this function calls THD::change_item_tree() on the passed Item **
+  pointers, it is necessary to pass the original Item **'s, not copies.
+  Otherwise their values will not be properly restored (see BUG#20769).
+  If the items are not consecutive (eg. args[2] and args[5]), use the
+  item_sep argument, ie.
+
+    agg_item_charsets(coll, fname, &args[2], 2, flags, 3)
+
+*/
+
+bool agg_item_charsets(DTCollation &coll, const char *fname,
+                       Item **args, uint nargs, uint flags, int item_sep)
+{
+  if (agg_item_collations(coll, fname, args, nargs, flags, item_sep))
+    return TRUE;
+
+  return agg_item_set_converter(coll, fname, args, nargs, flags, item_sep);
+}
+
+
 void Item_ident_for_show::make_field(Send_field *tmp_field)
 {
   tmp_field->table_name= tmp_field->org_table_name= table_name;
@@ -3084,7 +3100,7 @@ bool Item_param::convert_str_value(THD *thd)
       str_value.set_charset(value.cs_info.final_character_set_of_str_value);
     /* Here str_value is guaranteed to be in final_character_set_of_str_value */
 
-    max_length= str_value.length();
+    max_length= str_value.numchars() * str_value.charset()->mbmaxlen;
     decimals= 0;
     /*
       str_value_ptr is returned from val_str(). It must be not alloced