Bug #11765810 58813: SERVER THREAD HANGS WHEN JOIN + WHERE + GROUP BY

IS EXECUTED TWICE FROM P

This bug is a duplicate of bug 12567331, which was pushed to the
optimizer backporting tree on 2011-06-11. This is just a back-port of
the fix. Both test cases are included as they differ somewhat.

mysql-test/r/join_outer.result

@@ -1427,4 +1427,62 @@ WHERE t1.f1 = 4 AND t2.f1 IS NOT NULL AND t2.f2 IS NOT NULL
 GROUP BY t2.f1, t2.f2;
 f1	f1	f2
 DROP TABLE t1,t2;
+
+# BUG#12567331 - INFINITE LOOP WHEN RESOLVING AN ALIASED COLUMN
+# USED IN GROUP BY
+
+CREATE TABLE t1 (
+col_varchar_1024_latin1_key varchar(1024),
+col_varchar_10_latin1 varchar(10),
+col_int int(11),
+pk int(11)
+);
+CREATE TABLE t2 (
+col_int_key int(11),
+col_int int(11),
+pk int(11)
+);
+PREPARE prep_stmt_9846 FROM '
+SELECT alias1.pk AS field1 FROM
+t1 AS alias1
+LEFT JOIN
+( 
+  t2 AS alias2
+  RIGHT  JOIN
+  ( 
+    t2 AS alias3
+    JOIN t1 AS alias4
+    ON 1
+  )
+  ON 1
+)
+ON 1
+GROUP BY field1';
+execute prep_stmt_9846;
+field1
+execute prep_stmt_9846;
+field1
+drop table t1,t2;
+#
+# Bug #11765810	58813: SERVER THREAD HANGS WHEN JOIN + WHERE + GROUP BY
+# IS EXECUTED TWICE FROM P
+#
+CREATE TABLE t1 ( a INT ) ENGINE = MYISAM;
+INSERT INTO t1 VALUES (1);
+PREPARE prep_stmt FROM '
+ SELECT 1 AS f FROM t1
+ LEFT JOIN t1 t2
+  RIGHT JOIN t1 t3
+    JOIN t1 t4
+   ON 1
+  ON 1
+ ON 1
+ GROUP BY f';
+EXECUTE prep_stmt;
+f
+1
+EXECUTE prep_stmt;
+f
+1
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/join_outer.test

@@ -1010,4 +1010,62 @@ GROUP BY t2.f1, t2.f2;
 
 DROP TABLE t1,t2;
 
+
+--echo
+--echo # BUG#12567331 - INFINITE LOOP WHEN RESOLVING AN ALIASED COLUMN
+--echo # USED IN GROUP BY
+--echo 
+CREATE TABLE t1 (
+  col_varchar_1024_latin1_key varchar(1024),
+  col_varchar_10_latin1 varchar(10),
+  col_int int(11),
+  pk int(11)
+);
+CREATE TABLE t2 (
+  col_int_key int(11),
+  col_int int(11),
+  pk int(11)
+);
+
+PREPARE prep_stmt_9846 FROM '
+SELECT alias1.pk AS field1 FROM
+t1 AS alias1
+LEFT JOIN
+( 
+  t2 AS alias2
+  RIGHT  JOIN
+  ( 
+    t2 AS alias3
+    JOIN t1 AS alias4
+    ON 1
+  )
+  ON 1
+)
+ON 1
+GROUP BY field1';
+execute prep_stmt_9846;
+execute prep_stmt_9846;
+drop table t1,t2;
+
+--echo #
+--echo # Bug #11765810	58813: SERVER THREAD HANGS WHEN JOIN + WHERE + GROUP BY
+--echo # IS EXECUTED TWICE FROM P
+--echo #
+CREATE TABLE t1 ( a INT ) ENGINE = MYISAM;
+INSERT INTO t1 VALUES (1);
+PREPARE prep_stmt FROM '
+ SELECT 1 AS f FROM t1
+ LEFT JOIN t1 t2
+  RIGHT JOIN t1 t3
+    JOIN t1 t4
+   ON 1
+  ON 1
+ ON 1
+ GROUP BY f';
+EXECUTE prep_stmt;
+EXECUTE prep_stmt;
+
+DROP TABLE t1;
+
+
 --echo End of 5.1 tests

sql/sql_select.cc

@@ -8947,11 +8947,9 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
   }
     
   /* Flatten nested joins that can be flattened. */
-  TABLE_LIST *right_neighbor= NULL;
   li.rewind();
   while ((table= li++))
   {
-    bool fix_name_res= FALSE;
     nested_join= table->nested_join;
     if (nested_join && !table->on_expr)
     {
@@ -8963,15 +8961,7 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
         tbl->join_list= table->join_list;
       }
       li.replace(nested_join->join_list);
-      /* Need to update the name resolution table chain when flattening joins */
-      fix_name_res= TRUE;
-      table= *li.ref();
-    }
-    if (fix_name_res)
-      table->next_name_resolution_table= right_neighbor ?
-        right_neighbor->first_leaf_for_name_resolution() :
-        NULL;
-    right_neighbor= table;
+    }
   }
   DBUG_RETURN(conds); 
 }