Bugs#9129: CHARSET(), COLLATION(), COERCIBILITY()

not always correct for NULL values.
Now they always result a non NULL value even
the argument is NULL. It is more usefull for 
debugging purposes.

2 files changed, 7 insertions, 13 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index 96250522c4a..ade394f90d3 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -1346,11 +1346,6 @@ longlong Item_func_char_length::val_int()
 longlong Item_func_coercibility::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  if (args[0]->null_value)
-  {
-    null_value= 1;
-    return 0;
-  }
   null_value= 0;
   return (longlong) args[0]->collation.derivation;
 }
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index b4f75859469..8b9351d95a5 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -2290,12 +2290,11 @@ bool Item_func_set_collation::eq(const Item *item, bool binary_cmp) const
 String *Item_func_charset::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  String *res = args[0]->val_str(str);
   uint dummy_errors;
 
-  if ((null_value=(args[0]->null_value || !res->charset())))
-    return 0;
-  str->copy(res->charset()->csname,strlen(res->charset()->csname),
+  CHARSET_INFO *cs= args[0]->collation.collation; 
+  null_value= 0;
+  str->copy(cs->csname, strlen(cs->csname),
 	    &my_charset_latin1, collation.collation, &dummy_errors);
   return str;
 }
@@ -2303,12 +2302,11 @@ String *Item_func_charset::val_str(String *str)
 String *Item_func_collation::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  String *res = args[0]->val_str(str);
   uint dummy_errors;
+  CHARSET_INFO *cs= args[0]->collation.collation; 
 
-  if ((null_value=(args[0]->null_value || !res->charset())))
-    return 0;
-  str->copy(res->charset()->name,strlen(res->charset()->name),
+  null_value= 0;
+  str->copy(cs->name, strlen(cs->name),
 	    &my_charset_latin1, collation.collation, &dummy_errors);
   return str;
 }
@@ -2472,6 +2470,7 @@ String* Item_func_export_set::val_str(String* str)
   uint num_set_values = 64;
   ulonglong mask = 0x1;
   str->length(0);
+  str->set_charset(collation.collation);
 
   /* Check if some argument is a NULL value */
   if (args[0]->null_value || args[1]->null_value || args[2]->null_value)