Getting closer to be more SQL99 in dyadic operations

mysql-test/r/ctype_collate.result:
  NO COLLATION has less coercibility than IMPLICIT and COERCIBLE
sql/item.cc:
  Function to choose collation for dyadic operations
sql/item.h:
  NO COLLATION has less coercibility than IMPLICIT and COERCIBLE
sql/item_func.cc:
  Function to choose collation for dyadic operations
sql/item_strfunc.cc:
  Function to choose collation for dyadic operations
sql/item_strfunc.h:
  Use arg's attributes

1 files changed, 9 insertions, 2 deletions

diff --git a/sql/item.h b/sql/item.h
index 2bb22d47083..d9698e09ade 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -39,8 +39,8 @@ public:
              SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM};
 
   enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE };
-  enum coercion    { COER_NOCOLL=3,   COER_COERCIBLE=2, 
-  		     COER_IMPLICIT=1, COER_EXPLICIT=0  };
+  enum coercion    { COER_COERCIBLE=3, COER_IMPLICIT=2, 
+  		     COER_NOCOLL=1,    COER_EXPLICIT=0  };
 
   String str_value;			/* used to store value */
   my_string name;			/* Name from select */
@@ -113,6 +113,13 @@ public:
   CHARSET_INFO *default_charset() const;
   CHARSET_INFO *charset() const { return str_value.charset(); };
   void set_charset(CHARSET_INFO *cs) { str_value.set_charset(cs); }
+  void set_charset(CHARSET_INFO *cs, enum coercion coer)
+  {
+    str_value.set_charset(cs);
+    coercibility= coer;
+  }
+  bool set_charset(CHARSET_INFO *cs1, enum coercion co1, 
+  		   CHARSET_INFO *cs2, enum coercion co2);
   virtual void set_outer_resolving() {}
 
   // Row emulation