Allow index on 'CHAR(0) NULL' columns

Fixed error in Maria when using table with only CHAR(0) fields
Fixed valgrind warning


BitKeeper/etc/ignore:
  added storage/maria/maria_dump_log
mysql-test/r/maria.result:
  Testing of table with char(0)
mysql-test/t/maria.test:
  Testing of table with char(0)
sql/sql_table.cc:
  Allow index on 'CHAR(0) NULL' columns
storage/maria/ma_create.c:
  Allow creation of table with 0 record data (for example CHAR(0))
storage/maria/ma_pagecrc.c:
  Fixed valgrind warning

.bzrignore

@@ -3072,3 +3072,4 @@ libmysqld/sql_profile.cc
 *.exp
 comments
 maria-win.patch
+storage/maria/maria_dump_log

mysql-test/r/bdb_notembedded.result

+set autocommit=1;
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+drop table bug16206;
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+show binlog events;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+f	n	Format_desc	1	n	Server ver: VERSION, Binlog ver: 4
+f	n	Query	1	n	use `test`; create table bug16206 (a int) engine=         bdb
+f	n	Query	1	n	use `test`; insert into bug16206 values(0)
+f	n	Query	1	n	use `test`; insert into bug16206 values(1)
+f	n	Query	1	n	use `test`; BEGIN
+f	n	Query	1	n	use `test`; insert into bug16206 values(2)
+f	n	Query	1	n	use `test`; COMMIT
+f	n	Query	1	n	use `test`; insert into bug16206 values(3)
+drop table bug16206;
+set autocommit=0;
+End of 5.0 tests

mysql-test/r/maria.result

@@ -2071,6 +2071,37 @@ Maria_pagecache_read_requests	#
 Maria_pagecache_reads	#
 Maria_pagecache_write_requests	#
 Maria_pagecache_writes	#
+create table t1 (b char(0));
+insert into t1 values(NULL),("");
+select length(b) from t1;
+length(b)
+NULL
+0
+alter table t1 add column c char(0), add key (c);
+insert into t1 values("",""),("",NULL);
+select length(b),length(c) from t1;
+length(b)	length(c)
+NULL	NULL
+0	NULL
+0	0
+0	NULL
+select length(b),length(c) from t1 where c is null;
+length(b)	length(c)
+NULL	NULL
+0	NULL
+0	NULL
+select length(b),length(c) from t1 where c is not null;
+length(b)	length(c)
+0	0
+select length(b),length(c) from t1 order by c;
+length(b)	length(c)
+NULL	NULL
+0	NULL
+0	NULL
+0	0
+alter table t1 add column d char(0) not null, add key (d);
+ERROR 42000: The used storage engine can't index column 'd'
+drop table t1;
 set global maria_page_checksum=1;
 create table t1 (a int);
 show create table t1;

mysql-test/t/bdb_notembedded.test

+-- source include/not_embedded.inc
+-- source include/have_bdb.inc
+
+#
+# Bug #16206: Superfluous COMMIT event in binlog when updating BDB in autocommit mode
+#
+set autocommit=1;
+
+let $VERSION=`select version()`;
+
+reset master;
+create table bug16206 (a int);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+reset master;
+create table bug16206 (a int) engine=         bdb;
+insert into bug16206 values(0);
+insert into bug16206 values(1);
+start transaction;
+insert into bug16206 values(2);
+commit;
+insert into bug16206 values(3);
+--replace_result $VERSION VERSION
+--replace_column 1 f 2 n 5 n
+show binlog events;
+drop table bug16206;
+
+set autocommit=0;
+
+
+--echo End of 5.0 tests

mysql-test/t/maria.test

@@ -1315,6 +1315,23 @@ show variables like 'maria%';
 --replace_column 2 #
 show status like 'maria%';
 
+#
+# Test creating table with no field data and index on zero length columns
+#
+
+create table t1 (b char(0));
+insert into t1 values(NULL),("");
+select length(b) from t1;
+alter table t1 add column c char(0), add key (c);
+insert into t1 values("",""),("",NULL);
+select length(b),length(c) from t1;
+select length(b),length(c) from t1 where c is null;
+select length(b),length(c) from t1 where c is not null;
+select length(b),length(c) from t1 order by c;
+--error 1167
+alter table t1 add column d char(0) not null, add key (d);
+drop table t1;
+
 #
 # Show that page_checksum is remembered
 #

sql/sql_table.cc

@@ -2899,10 +2899,10 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
 	else if (!(file->ha_table_flags() & HA_NO_PREFIX_CHAR_KEYS))
 	  length=column->length;
       }
-      else if (length == 0)
+      else if (length == 0 && (sql_field->flags & NOT_NULL_FLAG))
       {
 	my_error(ER_WRONG_KEY_COLUMN, MYF(0), column->field_name);
-	  DBUG_RETURN(TRUE);
+        DBUG_RETURN(TRUE);
       }
       if (length > file->max_key_part_length() && key->type != Key::FULLTEXT)
       {

storage/maria/ma_create.c

@@ -85,7 +85,7 @@ int maria_create(const char *name, enum data_file_type datafile_type,
     ci=&tmp_create_info;
   }
 
-  if (keys + uniques > MARIA_MAX_KEY || columns == 0)
+  if (keys + uniques > MARIA_MAX_KEY)
   {
     DBUG_RETURN(my_errno=HA_WRONG_CREATE_OPTION);
   }

storage/maria/ma_pagecrc.c

@@ -305,6 +305,10 @@ my_bool maria_page_filler_set_none(uchar *page __attribute__((unused)),
                                    __attribute__((unused)),
                                    uchar *data_ptr __attribute__((unused)))
 {
+#ifdef HAVE_purify
+  int4store_aligned(page + ((MARIA_SHARE *)data_ptr)->block_size - CRC_SIZE,
+                    0);
+#endif
   return 0;
 }