wording fixed

sql/sql_cache.cc

@@ -1535,7 +1535,7 @@ ulong Query_cache::init_cache()
     On windows, OS/2, MacOS X with HFS+ or any other case insensitive
     file system if lower_case_table_names!=0 we have same situation as
     in previous case, but if lower_case_table_names==0 then we should
-    not distinguish cases (to be compatible in behavior with underlaying 
+    not distinguish cases (to be compatible in behavior with underlying
     file system) and so should use case insensitive collation for
     comparison.
   */

sql/sql_lex.cc

@@ -1562,7 +1562,7 @@ bool st_select_lex_unit::check_updateable(char *db, char *table)
 
 /*
   Find db.table which will be updated in this select and
-  underlaying ones (except derived tables)
+  underlying ones (except derived tables)
 
   SYNOPSIS
     st_select_lex::check_updateable()
@@ -1583,7 +1583,7 @@ bool st_select_lex::check_updateable(char *db, char *table)
 }
 
 /*
-   Find db.table which will be updated in underlaying subqueries
+   Find db.table which will be updated in underlying subqueries
 
    SYNOPSIS
     st_select_lex::check_updateable_in_subqueries()

sql/sql_parse.cc

@@ -2800,7 +2800,7 @@ unsent_create_error:
       target_tbl->table= orig->table;
       /*
 	 Multi-delete can't be constructed over-union => we always have
-	 single SELECT on top and have to check underlaying SELECTs of it
+	 single SELECT on top and have to check underlying SELECTs of it
       */
       if (lex->select_lex.check_updateable_in_subqueries(orig->db,
                                                          orig->real_name))