Automerge.

mysql-test/r/join.result

@@ -1235,4 +1235,24 @@ ORDER BY t1.a, t1.a LIMIT 1) AS d)
 1
 1
 DROP TABLE t1;
+#
+# Bug #53544: Server hangs during JOIN query in stored procedure called
+#             twice in a row
+#
+CREATE TABLE t1(c INT);
+INSERT INTO t1 VALUES (1), (2);
+PREPARE stmt FROM "SELECT t2.c AS f1 FROM t1 LEFT JOIN
+                                        t1 t2 ON t1.c=t2.c RIGHT JOIN
+                                        t1 t3 ON t1.c=t3.c 
+                   GROUP BY f1;";
+EXECUTE stmt;
+f1
+1
+2
+EXECUTE stmt;
+f1
+1
+2
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/join.test

@@ -897,4 +897,24 @@ GREATEST(t1.a,
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #53544: Server hangs during JOIN query in stored procedure called
+--echo #             twice in a row
+--echo #
+
+CREATE TABLE t1(c INT);
+
+INSERT INTO t1 VALUES (1), (2);
+
+PREPARE stmt FROM "SELECT t2.c AS f1 FROM t1 LEFT JOIN
+                                        t1 t2 ON t1.c=t2.c RIGHT JOIN
+                                        t1 t3 ON t1.c=t3.c 
+                   GROUP BY f1;";
+
+EXECUTE stmt;
+EXECUTE stmt;
+
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+
 --echo End of 5.1 tests

sql/sql_select.cc

@@ -8885,10 +8885,10 @@ 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;
-  bool fix_name_res= FALSE;
   li.rewind();
   while ((table= li++))
   {
+    bool fix_name_res= FALSE;
     nested_join= table->nested_join;
     if (nested_join && !table->on_expr)
     {