Bug#21505 Create view - illegal mix of collation for operation 'UNION'

  
  The problem was that any VIEW columns had always implicit derivation.
  Fix: derivation is now copied from the original expression
  given in VIEW definition.
  For example:
  - a VIEW column which comes from a string constant
    in CREATE VIEW definition have now coercible derivation.
  - a VIEW column having COLLATE clause
    in CREATE VIEW definition have now explicit derivation.


mysql-test/r/ctype_utf8.result:
  Adding test case
mysql-test/t/ctype_utf8.test:
  Adding test case
sql/field.cc:
  Copying derivation from item to field.
sql/field.h:
  Adding derivation and methods to get/set it into Field.
sql/item.cc:
  Copying derivation from field to item.
sql/item.h:
  Moving "enum Derivation" declaration from item.h to mysql_priv.h
sql/mysql_priv.h:
  Moving "enum Derivation" declaration from item.h to mysql_priv.h
sql/sql_select.cc:
  Copying derivation from item to field in
  create_tmp_field_from_item() and create_tmp_field().

1 files changed, 11 insertions, 0 deletions

diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 165bedb3659..683f111e4f3 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -96,6 +96,17 @@ extern CHARSET_INFO *system_charset_info, *files_charset_info ;
 extern CHARSET_INFO *national_charset_info, *table_alias_charset;
 
 
+enum Derivation
+{
+  DERIVATION_IGNORABLE= 5,
+  DERIVATION_COERCIBLE= 4,
+  DERIVATION_SYSCONST= 3,
+  DERIVATION_IMPLICIT= 2,
+  DERIVATION_NONE= 1,
+  DERIVATION_EXPLICIT= 0
+};
+
+
 typedef struct my_locale_st
 {
   const char *name;