Cleanup: Adding "const" to the member Spvar_definition::m_column_type_ref

and to related methods and their parameters:
- The return value of Spvar_definition::m_column_type_ref()
- The parameter of Spvar_definition::set_column_type_ref()
- The method Qualified_column_ident::resolve_type_ref()
- The parameter of LEX::sp_variable_declarations_column_type_finalize()

sql/field.h

@@ -5585,8 +5585,8 @@ class Row_definition_list: public List<class Spvar_definition>
 */
 class Spvar_definition: public Column_definition
 {
-  Qualified_column_ident *m_column_type_ref; // for %TYPE
-  Table_ident *m_table_rowtype_ref;          // for table%ROWTYPE
+  const Qualified_column_ident *m_column_type_ref; // for %TYPE
+  Table_ident *m_table_rowtype_ref;                // for table%ROWTYPE
   bool m_cursor_rowtype_ref;                       // for cursor%ROWTYPE
   uint m_cursor_rowtype_offset;                    // for cursor%ROWTYPE
   Row_definition_list *m_row_field_definitions;    // for ROW
@@ -5619,11 +5619,11 @@ class Spvar_definition: public Column_definition
            !is_table_rowtype_ref() &&
            !is_cursor_rowtype_ref();
   }
-  Qualified_column_ident *column_type_ref() const
+  const Qualified_column_ident *column_type_ref() const
   {
     return m_column_type_ref;
   }
-  void set_column_type_ref(Qualified_column_ident *ref)
+  void set_column_type_ref(const Qualified_column_ident *ref)
   {
     m_column_type_ref= ref;
   }

sql/sp_rcontext.cc

@@ -226,7 +226,8 @@ check_column_grant_for_type_ref(THD *thd, TABLE_LIST *table_list,
 /**
   This method implementation is very close to fill_schema_table_by_open().
 */
-bool Qualified_column_ident::resolve_type_ref(THD *thd, Column_definition *def)
+bool Qualified_column_ident::resolve_type_ref(THD *thd,
+                                              Column_definition *def) const
 {
   Open_tables_backup open_tables_state_backup;
   thd->reset_n_backup_open_tables_state(&open_tables_state_backup);

sql/sql_class.h

@@ -7142,7 +7142,7 @@ class Qualified_column_ident: public Table_ident
    :Table_ident(thd, db, table, false),
     m_column(*column)
   { }
-  bool resolve_type_ref(THD *thd, Column_definition *def);
+  bool resolve_type_ref(THD *thd, Column_definition *def) const;
   bool append_to(THD *thd, String *to) const;
 };
 

sql/sql_lex.cc

@@ -6715,9 +6715,9 @@ LEX::sp_variable_declarations_with_ref_finalize(THD *thd, int nvars,
 
 bool
 LEX::sp_variable_declarations_column_type_finalize(THD *thd, int nvars,
-                                                   Qualified_column_ident *ref,
-                                                   Item *def,
-                                                   const LEX_CSTRING &expr_str)
+                                              const Qualified_column_ident *ref,
+                                              Item *def,
+                                              const LEX_CSTRING &expr_str)
 {
   for (uint i= 0 ; i < (uint) nvars; i++)
   {
@@ -6757,7 +6757,7 @@ LEX::sp_variable_declarations_vartype_finalize(THD *thd, int nvars,
 
   if (t->field_def.is_column_type_ref())
   {
-    Qualified_column_ident *tmp= t->field_def.column_type_ref();
+    const Qualified_column_ident *tmp= t->field_def.column_type_ref();
     return sp_variable_declarations_column_type_finalize(thd, nvars, tmp,
                                                          default_value,
                                                          expr_str);

sql/sql_lex.h

@@ -3972,9 +3972,9 @@ struct LEX: public Query_tables_list
                                                        Item *def,
                                                        const LEX_CSTRING &expr_str);
   bool sp_variable_declarations_column_type_finalize(THD *thd, int nvars,
-                                                     Qualified_column_ident *ref,
-                                                     Item *def,
-                                                     const LEX_CSTRING &expr_str);
+                                              const Qualified_column_ident *ref,
+                                              Item *def,
+                                              const LEX_CSTRING &expr_str);
   bool sp_variable_declarations_vartype_finalize(THD *thd, int nvars,
                                                  const LEX_CSTRING &name,
                                                  Item *def,