Fix for bug #20695: Charset introducer overrides charset definition for column.

  - if there are two character set definitions in the column declaration,
    we replace the first one with the second one as we store both in the LEX->charset
    slot. Add a separate slot to the LEX structure to store underscore charset.
  - convert default values to the column charset of STRING, VARSTRING fields 
    if necessary as well.


mysql-test/r/ctype_recoding.result:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - test result.
mysql-test/t/ctype_recoding.test:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - test case.
sql/sql_lex.cc:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - LEX->underscore_charset introduced to store UNDERSCORE_CHARSET
sql/sql_lex.h:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - LEX->underscore_charset introduced to store UNDERSCORE_CHARSET
sql/sql_table.cc:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - convert default values to the column charset of VARSTRING, STRING, ENUM, 
      SET fields if necessary.
sql/sql_yacc.yy:
  Fix for bug #20695: Charset introducer overrides charset definition for column.
    - LEX->underscore_charset introduced to store UNDERSCORE_CHARSET

1 files changed, 34 insertions, 29 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 631d2d89bbb..a5cb0d45664 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -516,6 +516,40 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       DBUG_RETURN(-1);
     }
 
+    /*
+      Convert the default value character
+      set into the column character set if necessary.
+    */
+    if (sql_field->def && 
+        savecs != sql_field->def->collation.collation &&
+        (sql_field->sql_type == FIELD_TYPE_VAR_STRING ||
+         sql_field->sql_type == FIELD_TYPE_STRING ||
+         sql_field->sql_type == FIELD_TYPE_SET ||
+         sql_field->sql_type == FIELD_TYPE_ENUM))
+    {
+      Item_arena backup_arena;
+      bool need_to_change_arena=
+        !thd->current_arena->is_conventional_execution();
+      if (need_to_change_arena)
+      {
+        /* Assert that we don't do that at every PS execute */
+        DBUG_ASSERT(thd->current_arena->is_first_stmt_execute());
+        thd->set_n_backup_item_arena(thd->current_arena, &backup_arena);
+      }
+
+      sql_field->def= sql_field->def->safe_charset_converter(savecs);
+
+      if (need_to_change_arena)
+        thd->restore_backup_item_arena(thd->current_arena, &backup_arena);
+
+      if (sql_field->def == NULL)
+      {
+        /* Could not convert */
+        my_error(ER_INVALID_DEFAULT, MYF(0), sql_field->field_name);
+        DBUG_RETURN(-1);
+      }
+    }
+
     if (sql_field->sql_type == FIELD_TYPE_SET ||
         sql_field->sql_type == FIELD_TYPE_ENUM)
     {
@@ -580,35 +614,6 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
         sql_field->interval_list.empty(); // Don't need interval_list anymore
       }
 
-      /*
-        Convert the default value from client character
-        set into the column character set if necessary.
-      */
-      if (sql_field->def && cs != sql_field->def->collation.collation)
-      {
-        Item_arena backup_arena;
-        bool need_to_change_arena=
-          !thd->current_arena->is_conventional_execution();
-        if (need_to_change_arena)
-        {
-          /* Asser that we don't do that at every PS execute */
-          DBUG_ASSERT(thd->current_arena->is_first_stmt_execute());
-          thd->set_n_backup_item_arena(thd->current_arena, &backup_arena);
-        }
-
-        sql_field->def= sql_field->def->safe_charset_converter(cs);
-
-        if (need_to_change_arena)
-          thd->restore_backup_item_arena(thd->current_arena, &backup_arena);
-
-        if (sql_field->def == NULL)
-        {
-          /* Could not convert */
-          my_error(ER_INVALID_DEFAULT, MYF(0), sql_field->field_name);
-          DBUG_RETURN(-1);
-        }
-      }
-
       if (sql_field->sql_type == FIELD_TYPE_SET)
       {
         if (sql_field->def != NULL)