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.

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

mysql-test/t/merge.test

@@ -7,6 +7,8 @@ drop table if exists t1,t2,t3,t4,t5,t6;
 drop database if exists mysqltest;
 --enable_warnings
 
+let $MYSQLD_DATADIR= `select @@datadir`;
+
 create table t1 (a int not null primary key auto_increment, message char(20));
 create table t2 (a int not null primary key auto_increment, message char(20));
 INSERT INTO t1 (message) VALUES ("Testing"),("table"),("t1");
@@ -1633,4 +1635,59 @@ SHOW CREATE TRIGGER tr1;
 DROP TRIGGER tr1;
 DROP TABLE t1, t2, t3;
 
+--echo #
+--echo # BUG#48265 - MRG_MYISAM problem (works in 5.0.85, does't work in 5.1.40)
+--echo #
+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;
+SHOW CREATE TABLE m1;
+DROP TABLE m1;
+
+CREATE TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM `test/1`.m1;
+SHOW CREATE TABLE `test/1`.m1;
+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;
+SHOW CREATE TABLE m1;
+DROP TABLE m1;
+
+CREATE TEMPORARY TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
+SELECT * FROM `test/1`.m1;
+SHOW CREATE TABLE `test/1`.m1;
+DROP TABLE `test/1`.m1;
+DROP TABLE `test/1`.`t/1`;
+
+DROP DATABASE `test/1`;
+
+# Test compatibility. Use '@' instead of '/' (was not allowed in 5.0)
+
+CREATE TABLE `t@1`(a INT);
+copy_file std_data/bug48265.frm $MYSQLD_DATADIR/test/m1.frm;
+write_file $MYSQLD_DATADIR/test/m1.MRG;
+t@1
+EOF
+SELECT * FROM m1;
+SHOW CREATE TABLE m1;
+DROP TABLE `t@1`;
+
+CREATE DATABASE `test@1`;
+CREATE TABLE `test@1`.`t@1`(a INT);
+FLUSH TABLE m1;
+remove_file $MYSQLD_DATADIR/test/m1.MRG;
+write_file $MYSQLD_DATADIR/test/m1.MRG;
+./test@1/t@1
+EOF
+SELECT * FROM m1;
+SHOW CREATE TABLE m1;
+DROP TABLE m1;
+DROP TABLE `test@1`.`t@1`;
+DROP DATABASE `test@1`;
+
 --echo End of 5.1 tests

storage/myisammrg/ha_myisammrg.cc

@@ -214,36 +214,14 @@ const char *ha_myisammrg::index_type(uint key_number)
 static int myisammrg_parent_open_callback(void *callback_param,
                                           const char *filename)
 {
-  ha_myisammrg  *ha_myrg;
-  TABLE         *parent;
+  ha_myisammrg  *ha_myrg= (ha_myisammrg*) callback_param;
+  TABLE         *parent= ha_myrg->table_ptr();
   TABLE_LIST    *child_l;
-  const char    *db;
-  const char    *table_name;
   size_t        dirlen;
   char          dir_path[FN_REFLEN];
+  char          name_buf[NAME_LEN];
   DBUG_ENTER("myisammrg_parent_open_callback");
 
-  /* Extract child table name and database name from filename. */
-  dirlen= dirname_length(filename);
-  if (dirlen >= FN_REFLEN)
-  {
-    /* purecov: begin inspected */
-    DBUG_PRINT("error", ("name too long: '%.64s'", filename));
-    my_errno= ENAMETOOLONG;
-    DBUG_RETURN(1);
-    /* purecov: end */
-  }
-  table_name= filename + dirlen;
-  dirlen--; /* Strip off trailing '/'. */
-  memcpy(dir_path, filename, dirlen);
-  dir_path[dirlen]= '\0';
-  db= base_name(dir_path);
-  dirlen-= db - dir_path; /* This is now the length of 'db'. */
-  DBUG_PRINT("myrg", ("open: '%s'.'%s'", db, table_name));
-
-  ha_myrg= (ha_myisammrg*) callback_param;
-  parent= ha_myrg->table_ptr();
-
   /* Get a TABLE_LIST object. */
   if (!(child_l= (TABLE_LIST*) alloc_root(&parent->mem_root,
                                           sizeof(TABLE_LIST))))
@@ -255,13 +233,69 @@ static int myisammrg_parent_open_callback(void *callback_param,
   }
   bzero((char*) child_l, sizeof(TABLE_LIST));
 
-  /* Set database (schema) name. */
-  child_l->db_length= dirlen;
-  child_l->db= strmake_root(&parent->mem_root, db, dirlen);
-  /* Set table name. */
-  child_l->table_name_length= strlen(table_name);
-  child_l->table_name= strmake_root(&parent->mem_root, table_name,
+  /*
+    Depending on MySQL version, filename may be encoded by table name to
+    file name encoding or not. Always encoded if parent table is created
+    by 5.1.46+. Encoded if parent is created by 5.1.6+ and child table is
+    in different database.
+  */
+  if (!has_path(filename))
+  {
+    /* Child is in the same database as parent. */
+    child_l->db_length= parent->s->db.length;
+    child_l->db= strmake_root(&parent->mem_root, parent->s->db.str,
+                              child_l->db_length);
+    /* Child table name is encoded in parent dot-MRG starting with 5.1.46. */
+    if (parent->s->mysql_version >= 50146)
+    {
+      child_l->table_name_length= filename_to_tablename(filename, name_buf,
+                                                        sizeof(name_buf));
+      child_l->table_name= strmake_root(&parent->mem_root, name_buf,
+                                        child_l->table_name_length);
+    }
+    else
+    {
+      child_l->table_name_length= strlen(filename);
+      child_l->table_name= strmake_root(&parent->mem_root, filename,
+                                        child_l->table_name_length);
+    }
+  }
+  else
+  {
+    DBUG_ASSERT(strlen(filename) < sizeof(dir_path));
+    fn_format(dir_path, filename, "", "", 0);
+    /* Extract child table name and database name from filename. */
+    dirlen= dirname_length(dir_path);
+    /* Child db/table name is encoded in parent dot-MRG starting with 5.1.6. */
+    if (parent->s->mysql_version >= 50106)
+    {
+      child_l->table_name_length= filename_to_tablename(dir_path + dirlen,
+                                                        name_buf,
+                                                        sizeof(name_buf));
+      child_l->table_name= strmake_root(&parent->mem_root, name_buf,
                                         child_l->table_name_length);
+      dir_path[dirlen - 1]= 0;
+      dirlen= dirname_length(dir_path);
+      child_l->db_length= filename_to_tablename(dir_path + dirlen, name_buf,
+                                                sizeof(name_buf));
+      child_l->db= strmake_root(&parent->mem_root, name_buf, child_l->db_length);
+    }
+    else
+    {
+      child_l->table_name_length= strlen(dir_path + dirlen);
+      child_l->table_name= strmake_root(&parent->mem_root, dir_path + dirlen,
+                                        child_l->table_name_length);
+      dir_path[dirlen - 1]= 0;
+      dirlen= dirname_length(dir_path);
+      child_l->db_length= strlen(dir_path + dirlen);
+      child_l->db= strmake_root(&parent->mem_root, dir_path + dirlen,
+                                child_l->db_length);
+    }
+  }
+
+  DBUG_PRINT("myrg", ("open: '%.*s'.'%.*s'", child_l->db_length, child_l->db,
+                      child_l->table_name_length, child_l->table_name));
+
   /* Convert to lowercase if required. */
   if (lower_case_table_names && child_l->table_name_length)
     child_l->table_name_length= my_casedn_str(files_charset_info,
@@ -1132,7 +1166,7 @@ int ha_myisammrg::create(const char *name, register TABLE *form,
   /* Create child path names. */
   for (pos= table_names; tables; tables= tables->next_local)
   {
-    const char *table_name;
+    const char *table_name= buff;
 
     /*
       Construct the path to the MyISAM table. Try to meet two conditions:
@@ -1158,9 +1192,11 @@ int ha_myisammrg::create(const char *name, register TABLE *form,
       as the MyISAM tables are from the same database as the MERGE table.
     */
     if ((dirname_length(buff) == dirlgt) && ! memcmp(buff, name, dirlgt))
-      table_name= tables->table_name;
-    else
-      if (! (table_name= thd->strmake(buff, length)))
+    {
+      table_name+= dirlgt;
+      length-= dirlgt;
+    }
+    if (!(table_name= thd->strmake(table_name, length)))
       DBUG_RETURN(HA_ERR_OUT_OF_MEM); /* purecov: inspected */
 
     *pos++= table_name;
@@ -1182,7 +1218,7 @@ void ha_myisammrg::append_create_info(String *packet)
   const char *current_db;
   size_t db_length;
   THD *thd= current_thd;
-  MYRG_TABLE *open_table, *first;
+  TABLE_LIST *open_table, *first;
 
   if (file->merge_insert_method != MERGE_INSERT_DISABLED)
   {
@@ -1200,14 +1236,11 @@ void ha_myisammrg::append_create_info(String *packet)
   current_db= table->s->db.str;
   db_length=  table->s->db.length;
 
-  for (first=open_table=file->open_tables ;
-       open_table != file->end_table ;
-       open_table++)
+  for (first= open_table= table->child_l;;
+       open_table= open_table->next_global)
   {
-    LEX_STRING db, name;
-    LINT_INIT(db.str);
+    LEX_STRING db= { open_table->db, open_table->db_length };
 
-    split_file_name(open_table->table->filename, &db, &name);
     if (open_table != first)
       packet->append(',');
     /* Report database for mapped table if it isn't in current database */
@@ -1218,7 +1251,10 @@ void ha_myisammrg::append_create_info(String *packet)
       append_identifier(thd, packet, db.str, db.length);
       packet->append('.');
     }
-    append_identifier(thd, packet, name.str, name.length);
+    append_identifier(thd, packet, open_table->table_name,
+                      open_table->table_name_length);
+    if (&open_table->next_global == table->child_last_l)
+      break;
   }
   packet->append(')');
 }

storage/myisammrg/myrg_open.c

@@ -311,14 +311,6 @@ MYRG_INFO *myrg_parent_open(const char *parent_name,
     if (!child_name_buff[0] || (child_name_buff[0] == '#'))
       continue;
 
-    if (!has_path(child_name_buff))
-    {
-      VOID(strmake(parent_name_buff + dir_length, child_name_buff,
-                   sizeof(parent_name_buff) - 1 - dir_length));
-      VOID(cleanup_dirname(child_name_buff, parent_name_buff));
-    }
-    else
-      fn_format(child_name_buff, child_name_buff, "", "", 0);
     DBUG_PRINT("info", ("child: '%s'", child_name_buff));
 
     /* Callback registers child with handler table. */