Bug#48459: valgrind errors with query using 'Range checked

for each record'

There was an error in an internal structure in the range
optimizer (SEL_ARG). Bad design causes parts of a data
structure not to be initialized when it is in a certain
state. All client code must check that this state is not
present before trying to access the structure's data. Fixed
by

- Checking the state before trying to access data (in
several places, most of which not covered by test case.)

- Copying the keypart id when cloning SEL_ARGs


mysql-test/r/range.result:
  Bug#48459: Test result.
mysql-test/t/range.test:
  Bug#48459: Test case.
sql/opt_range.cc:
  Bug#48459: Fix + doxygenated count_key_part_usage comment.

2 files changed, 66 insertions, 1 deletions

diff --git a/mysql-test/r/range.result b/mysql-test/r/range.result
index ab40eefdc82..64e00521cd2 100644
--- a/mysql-test/r/range.result
+++ b/mysql-test/r/range.result
@@ -1604,6 +1604,39 @@ str_to_date('', '%Y-%m-%d')
 0000-00-00
 DROP TABLE t1, t2;
 #
+# Bug#48459: valgrind errors with query using 'Range checked for each 
+# record'
+#
+CREATE TABLE t1 (
+a INT,
+b CHAR(2),
+c INT,
+d INT,
+KEY ( c ),
+KEY ( d, a, b ( 2 ) ),
+KEY ( b ( 1 ) )
+);
+INSERT INTO t1 VALUES ( NULL, 'a', 1, 2 ), ( NULL, 'a', 1, 2 ),
+( 1,    'a', 1, 2 ), ( 1,    'a', 1, 2 );
+CREATE TABLE t2 (
+a INT,
+c INT,
+e INT,
+KEY ( e )
+);
+INSERT INTO t2 VALUES ( 1, 1, NULL ), ( 1, 1, NULL );
+# Should not give Valgrind warnings
+SELECT 1
+FROM t1, t2
+WHERE t1.d <> '1' AND t1.b > '1'
+AND t1.a = t2.a AND t1.c = t2.c;
+1
+1
+1
+1
+1
+DROP TABLE t1, t2;
+#
 # Bug #48665: sql-bench's insert test fails due to wrong result
 #
 CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a));
diff --git a/mysql-test/t/range.test b/mysql-test/t/range.test
index 736d65792c5..5d5ad180f1a 100644
--- a/mysql-test/t/range.test
+++ b/mysql-test/t/range.test
@@ -1260,6 +1260,39 @@ SELECT str_to_date('', '%Y-%m-%d');
 
 DROP TABLE t1, t2;
 
+--echo #
+--echo # Bug#48459: valgrind errors with query using 'Range checked for each 
+--echo # record'
+--echo #
+CREATE TABLE t1 (
+  a INT,
+  b CHAR(2),
+  c INT,
+  d INT,
+  KEY ( c ),
+  KEY ( d, a, b ( 2 ) ),
+  KEY ( b ( 1 ) )
+);
+
+INSERT INTO t1 VALUES ( NULL, 'a', 1, 2 ), ( NULL, 'a', 1, 2 ),
+                      ( 1,    'a', 1, 2 ), ( 1,    'a', 1, 2 );
+
+CREATE TABLE t2 (
+  a INT,
+  c INT,
+  e INT,
+  KEY ( e )
+);
+
+INSERT INTO t2 VALUES ( 1, 1, NULL ), ( 1, 1, NULL );
+
+--echo # Should not give Valgrind warnings
+SELECT 1
+FROM t1, t2
+WHERE t1.d <> '1' AND t1.b > '1'
+AND t1.a = t2.a AND t1.c = t2.c;
+
+DROP TABLE t1, t2;
 
 --echo #
 --echo # Bug #48665: sql-bench's insert test fails due to wrong result
@@ -1280,5 +1313,4 @@ SELECT * FROM t1 FORCE INDEX (PRIMARY)
 
 DROP TABLE t1;
 
-
 --echo End of 5.1 tests