Fixed LP bug #707848.

This was another bug in the patch for bug 698882. The new
code from this patch did not ensured that substitutions
of fields for best equal fields were performed on all
AND-OR levels. As a result substitutions for best fields
in some predicates that had been used by the range optimizer
were not actually performed while range plans could employ
these substitutions. This could lead to inconsistent data
structures and ultimately to a crash.

mysql-test/r/order_by.result

@@ -1643,4 +1643,34 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	a	8	NULL	10	Using index; Using temporary; Using filesort
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	Using where
 DROP TABLE t1, t2;
+#
+# Bug #707848: WHERE condition with OR + ORDER BY + field substitution  
+#
+CREATE TABLE t1 (a int PRIMARY KEY);
+INSERT INTO t1 VALUES
+(9), (7), (11), (15), (2), (4), (1), (5), (14), (54), (3), (8);
+EXPLAIN EXTENDED
+SELECT * FROM t1 r JOIN t1 s ON r.a = s.a 
+WHERE s.a IN (2,9) OR s.a < 100  AND s.a != 0
+ORDER BY 1 LIMIT 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	r	index	PRIMARY	PRIMARY	4	NULL	10	120.00	Using where; Using index
+1	SIMPLE	s	eq_ref	PRIMARY	PRIMARY	4	test.r.a	1	100.00	Using index
+Warnings:
+Note	1003	select `test`.`r`.`a` AS `a`,`test`.`s`.`a` AS `a` from `test`.`t1` `r` join `test`.`t1` `s` where ((`test`.`s`.`a` = `test`.`r`.`a`) and ((`test`.`r`.`a` in (2,9)) or ((`test`.`r`.`a` < 100) and (`test`.`r`.`a` <> 0)))) order by 1 limit 10
+SELECT * FROM t1 r JOIN t1 s ON r.a = s.a 
+WHERE s.a IN (2,9) OR s.a < 100 AND s.a != 0
+ORDER BY 1 LIMIT 10;
+a	a
+1	1
+2	2
+3	3
+4	4
+5	5
+7	7
+8	8
+9	9
+11	11
+14	14
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/order_by.test

@@ -1497,5 +1497,23 @@ LIMIT 2;
 
 DROP TABLE t1, t2;
 
+--echo #
+--echo # Bug #707848: WHERE condition with OR + ORDER BY + field substitution  
+--echo #
+
+CREATE TABLE t1 (a int PRIMARY KEY);
+INSERT INTO t1 VALUES
+  (9), (7), (11), (15), (2), (4), (1), (5), (14), (54), (3), (8);
+
+EXPLAIN EXTENDED
+SELECT * FROM t1 r JOIN t1 s ON r.a = s.a 
+  WHERE s.a IN (2,9) OR s.a < 100  AND s.a != 0
+    ORDER BY 1 LIMIT 10;
+
+SELECT * FROM t1 r JOIN t1 s ON r.a = s.a 
+  WHERE s.a IN (2,9) OR s.a < 100 AND s.a != 0
+    ORDER BY 1 LIMIT 10;
+
+DROP TABLE t1;
 
 --echo End of 5.1 tests

sql/sql_select.cc

@@ -9902,12 +9902,16 @@ static COND* substitute_for_best_equal_field(COND *cond,
     cond= eliminate_item_equal(0, cond_equal, item_equal);
     return cond ? cond : org_cond;
   }
-  else if (cond_equal)
+  else 
   {
-    List_iterator_fast<Item_equal> it(cond_equal->current_level);
-    while((item_equal= it++))
+    while (cond_equal)
     {
-      cond= cond->transform(&Item::replace_equal_field, (uchar *) item_equal);
+      List_iterator_fast<Item_equal> it(cond_equal->current_level);
+      while((item_equal= it++))
+      {
+        cond= cond->transform(&Item::replace_equal_field, (uchar *) item_equal);
+      }
+      cond_equal= cond_equal->upper_levels;
     }
   }
   return cond;