Fix for bug #54007: assert in ha_myisam::index_next, HANDLER

Problem: the server missed the fact that one can read from 
2 indexes alternately using HANDLER interface.

Fix: check if the same (initialized) index is involved
reading next/prev values from the index.


mysql-test/r/handler_myisam.result:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - test result.
mysql-test/t/handler_myisam.test:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - test case.
sql/sql_handler.cc:
  Fix for bug #54007: assert in ha_myisam::index_next, HANDLER
    - check if we use the same (initialized) index 
  to read next/prev values from the index.

2 files changed, 142 insertions, 0 deletions

diff --git a/mysql-test/r/handler_myisam.result b/mysql-test/r/handler_myisam.result
index a970e20a2c0..b20b8dbb138 100644
--- a/mysql-test/r/handler_myisam.result
+++ b/mysql-test/r/handler_myisam.result
@@ -769,4 +769,97 @@ a
 1
 HANDLER t1 CLOSE;
 DROP TABLE t1;
+#
+# Bug #54007: assert in ha_myisam::index_next , HANDLER
+#
+CREATE TABLE t1(a INT, b INT, PRIMARY KEY(a), KEY b(b), KEY ab(a, b));
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+a	b
+HANDLER t1 READ `PRIMARY` NEXT;
+a	b
+HANDLER t1 READ ab NEXT;
+a	b
+HANDLER t1 READ b NEXT;
+a	b
+HANDLER t1 READ NEXT;
+a	b
+HANDLER t1 CLOSE;
+INSERT INTO t1 VALUES (2, 20), (1, 10), (4, 40), (3, 30);
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+a	b
+2	20
+HANDLER t1 READ NEXT;
+a	b
+1	10
+HANDLER t1 READ `PRIMARY` NEXT;
+a	b
+1	10
+HANDLER t1 READ `PRIMARY` NEXT;
+a	b
+2	20
+HANDLER t1 READ ab NEXT;
+a	b
+1	10
+HANDLER t1 READ ab NEXT;
+a	b
+2	20
+HANDLER t1 READ b NEXT;
+a	b
+1	10
+HANDLER t1 READ b NEXT;
+a	b
+2	20
+HANDLER t1 READ b NEXT;
+a	b
+3	30
+HANDLER t1 READ b NEXT;
+a	b
+4	40
+HANDLER t1 READ b NEXT;
+a	b
+HANDLER t1 READ NEXT;
+a	b
+4	40
+HANDLER t1 READ NEXT;
+a	b
+3	30
+HANDLER t1 READ NEXT;
+a	b
+HANDLER t1 CLOSE;
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+a	b
+2	20
+HANDLER t1 READ `PRIMARY` PREV;
+a	b
+4	40
+HANDLER t1 READ `PRIMARY` PREV;
+a	b
+3	30
+HANDLER t1 READ b PREV;
+a	b
+4	40
+HANDLER t1 READ b PREV;
+a	b
+3	30
+HANDLER t1 CLOSE;
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+a	b
+2	20
+HANDLER t1 READ `PRIMARY` PREV LIMIT 3;
+a	b
+4	40
+3	30
+2	20
+HANDLER t1 READ b NEXT LIMIT 5;
+a	b
+1	10
+2	20
+3	30
+4	40
+HANDLER t1 CLOSE;
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/mysql-test/t/handler_myisam.test b/mysql-test/t/handler_myisam.test
index 868ba14480a..e78072ef8a0 100644
--- a/mysql-test/t/handler_myisam.test
+++ b/mysql-test/t/handler_myisam.test
@@ -48,4 +48,53 @@ HANDLER t1 READ a NEXT;
 HANDLER t1 CLOSE;
 DROP TABLE t1;
 
+
+--echo #
+--echo # Bug #54007: assert in ha_myisam::index_next , HANDLER
+--echo #
+CREATE TABLE t1(a INT, b INT, PRIMARY KEY(a), KEY b(b), KEY ab(a, b));
+
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+HANDLER t1 READ `PRIMARY` NEXT;
+HANDLER t1 READ ab NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ NEXT;
+HANDLER t1 CLOSE;
+
+INSERT INTO t1 VALUES (2, 20), (1, 10), (4, 40), (3, 30);
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+HANDLER t1 READ NEXT;
+HANDLER t1 READ `PRIMARY` NEXT;
+HANDLER t1 READ `PRIMARY` NEXT;
+HANDLER t1 READ ab NEXT;
+HANDLER t1 READ ab NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ b NEXT;
+HANDLER t1 READ NEXT;
+HANDLER t1 READ NEXT;
+HANDLER t1 READ NEXT;
+HANDLER t1 CLOSE;
+
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+HANDLER t1 READ `PRIMARY` PREV;
+HANDLER t1 READ `PRIMARY` PREV;
+HANDLER t1 READ b PREV;
+HANDLER t1 READ b PREV;
+HANDLER t1 CLOSE;
+
+HANDLER t1 OPEN;
+HANDLER t1 READ FIRST;
+HANDLER t1 READ `PRIMARY` PREV LIMIT 3;
+HANDLER t1 READ b NEXT LIMIT 5;
+HANDLER t1 CLOSE;
+
+DROP TABLE t1;
+
+
 --echo End of 5.1 tests