BUG#48265 - MRG_MYISAM problem (works in 5.0.85, does't

            work in 5.1.40)

MERGE engine fails to open child table from a different
database if child table/database name contains characters
that are subject for table name to filename encoding
(WL1324).

Another problem is that MERGE engine didn't properly open
child table from the same database if child table name
contains characters like '/', '#'.

The problem was that table name to file name encoding was
applied inconsistently:
* On CREATE: encode table name + database name if child
  table is in different database; do not encode table
  name if child table is in the same database;
* No decoding on open.

With this fix child table/database names are always
encoded on CREATE and decoded on open. Compatibility
with older tables preserved.

Along with this patch comes fix for SHOW CREATE TABLE,
which used to show child table/database path instead
of child table/database names.

mysql-test/r/merge.result:
  A test case for BUG#48265.
mysql-test/std_data/bug48265.frm:
  MERGE table from 5.0 to test fix for BUG#48265 compatibility.
mysql-test/t/merge.test:
  A test case for BUG#48265.
storage/myisammrg/ha_myisammrg.cc:
  On CREATE always write child table/database name encoded
  by table name to filename encoding to dot-MRG file.
  
  On open decode child table/database name.
  Compatibilty with previous versions preserved.
  
  Fixed ::append_create_info() to return child
  table/database name instead of path.
storage/myisammrg/myrg_open.c:
  Move if (has_path) branch from myrg_parent_open() to
  myisammrg_parent_open_callback. The callback function
  needs to know if child table was written along with
  database name to dot-MRG file. Needed for compatibility
  reasons.

1 files changed, 67 insertions, 0 deletions

diff --git a/mysql-test/r/merge.result b/mysql-test/r/merge.result
index 893ea5acf88..184cd92e053 100644
--- a/mysql-test/r/merge.result
+++ b/mysql-test/r/merge.result
@@ -2219,4 +2219,71 @@ Trigger	sql_mode	SQL Original Statement	character_set_client	collation_connectio
 tr1		CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER INSERT ON t3 FOR EACH ROW CALL foo()	latin1	latin1_swedish_ci	latin1_swedish_ci
 DROP TRIGGER tr1;
 DROP TABLE t1, t2, t3;
+#
+# BUG#48265 - MRG_MYISAM problem (works in 5.0.85, does't work in 5.1.40)
+#
+CREATE DATABASE `test/1`;
+CREATE TABLE `test/1`.`t/1`(a INT);
+CREATE TABLE m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM m1;
+a
+SHOW CREATE TABLE m1;
+Table	Create Table
+m1	CREATE TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test/1`.`t/1`)
+DROP TABLE m1;
+CREATE TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM `test/1`.m1;
+a
+SHOW CREATE TABLE `test/1`.m1;
+Table	Create Table
+m1	CREATE TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t/1`)
+DROP TABLE `test/1`.m1;
+DROP TABLE `test/1`.`t/1`;
+CREATE TEMPORARY TABLE `test/1`.`t/1`(a INT);
+CREATE TEMPORARY TABLE m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM m1;
+a
+SHOW CREATE TABLE m1;
+Table	Create Table
+m1	CREATE TEMPORARY TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test/1`.`t/1`)
+DROP TABLE m1;
+CREATE TEMPORARY TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM `test/1`.m1;
+a
+SHOW CREATE TABLE `test/1`.m1;
+Table	Create Table
+m1	CREATE TEMPORARY TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t/1`)
+DROP TABLE `test/1`.m1;
+DROP TABLE `test/1`.`t/1`;
+DROP DATABASE `test/1`;
+CREATE TABLE `t@1`(a INT);
+SELECT * FROM m1;
+a
+SHOW CREATE TABLE m1;
+Table	Create Table
+m1	CREATE TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t@1`)
+DROP TABLE `t@1`;
+CREATE DATABASE `test@1`;
+CREATE TABLE `test@1`.`t@1`(a INT);
+FLUSH TABLE m1;
+SELECT * FROM m1;
+a
+SHOW CREATE TABLE m1;
+Table	Create Table
+m1	CREATE TABLE `m1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test@1`.`t@1`)
+DROP TABLE m1;
+DROP TABLE `test@1`.`t@1`;
+DROP DATABASE `test@1`;
 End of 5.1 tests