Fixed LP bug #752353.

In some cases the field max_part_no of the SEL_ARG structure
was not initialized. That triggered a Valgrind complain.

mysql-test/r/range_vs_index_merge.result

@@ -1367,4 +1367,14 @@ f1	f2	f3	f4
 9	0	2	6
 SET SESSION optimizer_switch=DEFAULT;
 DROP TABLE t1;
+CREATE TABLE t1 (f1 int) ;
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (f1 int, f2 int, f3 int, f4 int, INDEX idx (f3,f2)) ;
+INSERT INTO t2 VALUES (5,6,0,0), (0,4,0,0);
+CREATE TABLE t3 (f1 int, f2 int, INDEX idx1 (f2,f1) , INDEX idx2 (f1)) ;
+INSERT INTO t3 VALUES (6,0),( 4,0);
+SELECT * FROM t1,t2,t3
+WHERE (t2.f3 = 1 OR t3.f1=t2.f1) AND t3.f1 <> t2.f2 AND t3.f2 = t2.f4;
+f1	f1	f2	f3	f4	f1	f2
+DROP TABLE t1,t2,t3;
 set session optimizer_switch='index_merge_sort_intersection=default';

mysql-test/r/range_vs_index_merge_innodb.result

@@ -1368,5 +1368,15 @@ f1	f2	f3	f4
 9	0	2	6
 SET SESSION optimizer_switch=DEFAULT;
 DROP TABLE t1;
+CREATE TABLE t1 (f1 int) ;
+INSERT INTO t1 VALUES (0), (0);
+CREATE TABLE t2 (f1 int, f2 int, f3 int, f4 int, INDEX idx (f3,f2)) ;
+INSERT INTO t2 VALUES (5,6,0,0), (0,4,0,0);
+CREATE TABLE t3 (f1 int, f2 int, INDEX idx1 (f2,f1) , INDEX idx2 (f1)) ;
+INSERT INTO t3 VALUES (6,0),( 4,0);
+SELECT * FROM t1,t2,t3
+WHERE (t2.f3 = 1 OR t3.f1=t2.f1) AND t3.f1 <> t2.f2 AND t3.f2 = t2.f4;
+f1	f1	f2	f3	f4	f1	f2
+DROP TABLE t1,t2,t3;
 set session optimizer_switch='index_merge_sort_intersection=default';
 SET SESSION STORAGE_ENGINE=DEFAULT;

mysql-test/t/range_vs_index_merge.test

@@ -1010,5 +1010,24 @@ SET SESSION optimizer_switch=DEFAULT;
 
 DROP TABLE t1;
 
+#
+# Bug #752353: valgrind complain on a jump depending 
+#             on an uninitialised value 
+#
+
+CREATE TABLE t1 (f1 int) ;
+INSERT INTO t1 VALUES (0), (0);
+
+CREATE TABLE t2 (f1 int, f2 int, f3 int, f4 int, INDEX idx (f3,f2)) ;
+INSERT INTO t2 VALUES (5,6,0,0), (0,4,0,0);
+
+CREATE TABLE t3 (f1 int, f2 int, INDEX idx1 (f2,f1) , INDEX idx2 (f1)) ;
+INSERT INTO t3 VALUES (6,0),( 4,0);
+
+SELECT * FROM t1,t2,t3
+  WHERE (t2.f3 = 1 OR t3.f1=t2.f1) AND t3.f1 <> t2.f2 AND t3.f2 = t2.f4; 
+
+DROP TABLE t1,t2,t3;
+
 #the following command must be the last one in the file
 set session optimizer_switch='index_merge_sort_intersection=default';

sql/opt_range.cc

@@ -7338,6 +7338,7 @@ get_mm_parts(RANGE_OPT_PARAM *param, COND *cond_func, Field *field,
 	  DBUG_RETURN(0);			// OOM
       }
       sel_arg->part=(uchar) key_part->part;
+      sel_arg->max_part_no= sel_arg->part+1;
       tree->keys[key_part->key]=sel_add(tree->keys[key_part->key],sel_arg);
       tree->keys_map.set_bit(key_part->key);
     }