Commit 4842d3da authored by tim@threads.polyesthetic.msg's avatar tim@threads.polyesthetic.msg
Browse files

Fix rare infinite loop in make_join_statistics(). Thanks to 

Paul Cadach <paul@odt.east.telecom.kz> for the code.

See Message-ID: <000a01c0a022$c0b910a0$b78313d4@private3se6v3w>
on internals@lists.mysql.com.
parent fd45aed7

sql/sql_select.cc

+4 −1
Original line number Diff line number Diff line
@@ -945,8 +945,10 @@ make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds, 
      DBUG_RETURN(1);



  /* loop until no more const tables are found */

  int ref_changed;

  do

  {

    ref_changed = 0;

    found_ref=0;

    for (JOIN_TAB **pos=stat_vector+const_count; (s= *pos) ; pos++)

    {
@@ -996,6 +998,7 @@ make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds, 
	      s->type=JT_CONST;

	      const_table_map|=table->map;

	      set_position(join,const_count++,s,start_keyuse);

	      ref_changed = 1;

	      break;

	    }

	    else
@@ -1004,7 +1007,7 @@ make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds, 
	}

      }

    }

  } while (const_table_map & found_ref);

  } while (const_table_map & found_ref && ref_changed);



  /* Calc how many (possible) matched records in each table */