Another attempt to fix bug mdev-5103.

The earlier pushed fix for the bug was incomplete. It did not remove
the main cause of the problem: the function remove_eq_conds()
removed always true multiple equalities from any conjunct, but did not
adjust the list of them stored in Item_cond_and::cond_equal.current_level.

Simplified the test case for the bug and moved it to another test file.

The fix triggered changes in EXPLAIN EXTENDED for some queries. 

2 files changed, 24 insertions, 50 deletions

diff --git a/mysql-test/t/func_equal.test b/mysql-test/t/func_equal.test
index 990b6d8e74e..f17ebb5bd84 100644
--- a/mysql-test/t/func_equal.test
+++ b/mysql-test/t/func_equal.test
@@ -44,53 +44,3 @@ select * from t1 where a in ('4828532208463511553');
 drop table t1;
 
 --echo #End of 4.1 tests
-
---echo #
---echo # MDEV-5103: server crashed on singular Item_equal
---echo #
-
-CREATE TABLE `t1` (
-  `tipo` enum('p','r') NOT NULL DEFAULT 'r',
-  `arquivo_id` bigint(20) unsigned NOT NULL DEFAULT '0',
-  `arquivo_md5` char(32) NOT NULL,
-  `conteudo` longblob NOT NULL,
-  `usuario` varchar(15) NOT NULL,
-  `datahora_gmt` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
-  `tipo_arquivo` varchar(255) NOT NULL,
-  `nome_arquivo` varchar(255) NOT NULL,
-  `tamanho_arquivo` bigint(20) unsigned NOT NULL DEFAULT '0',
-  PRIMARY KEY (`tipo`,`arquivo_id`),
-  UNIQUE KEY `tipo` (`tipo`,`arquivo_md5`)
-) ENGINE=Aria DEFAULT CHARSET=latin1 PAGE_CHECKSUM=1;
-
-INSERT INTO `t1` (`tipo`, `arquivo_id`, `arquivo_md5`, `conteudo`, `usuario`, `datahora_gmt`, `tipo_arquivo`, `nome_arquivo`, `tamanho_arquivo`) VALUES
-	('r', 1, 'ad18832202b199728921807033a8a515', '', 'rspadim', '2013-10-05 13:55:50', '001_cbr643', 'CBR6431677410201314132.ret', 21306);
-
-
-CREATE TABLE `t2` (
-  `tipo` enum('p','r') NOT NULL DEFAULT 'p',
-  `arquivo_id` bigint(20) NOT NULL DEFAULT '0',
-  `usuario` varchar(25) NOT NULL,
-  `datahora` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
-  `erros` longblob NOT NULL,
-  `importados` bigint(20) unsigned NOT NULL DEFAULT '0',
-  `n_importados` bigint(20) unsigned NOT NULL DEFAULT '0',
-  PRIMARY KEY (`tipo`,`arquivo_id`,`datahora`)
-) ENGINE=Aria DEFAULT CHARSET=latin1 PAGE_CHECKSUM=1;
-
-INSERT INTO `t2` (`tipo`, `arquivo_id`, `usuario`, `datahora`, `erros`, `importados`, `n_importados`) VALUES
-	('r', 1, 'rspadim', '2013-10-05 14:25:30', '', 32, 0);
-
-SELECT
-arquivo_id,usuario,datahora_gmt,tipo_arquivo,nome_arquivo,tamanho_arquivo
-  FROM t1 AS a
-  WHERE datahora_gmt>='0000-00-00 00:00:00' AND
-    datahora_gmt<='2013-10-07 02:59:59' AND tipo='r' AND
-    (tipo_arquivo,arquivo_id) NOT IN
-      (SELECT tipo_arquivo,arquivo_id
-        FROM t2
-        WHERE (tipo_arquivo,arquivo_id)=(a.tipo_arquivo,a.arquivo_id))
-  ORDER BY arquivo_id DESC;
-
-drop table t2, t1;
---echo #End of 5.3 tests
diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test
index 51247e2c3ea..ad0e135f37e 100644
--- a/mysql-test/t/subselect4.test
+++ b/mysql-test/t/subselect4.test
@@ -1910,7 +1910,31 @@ WHERE b IS NULL OR a < 'u';
 drop table t1,t2;
 set @@optimizer_switch = @optimizer_switch_MDEV4056;
 
+--echo #
+--echo # MDEV-5103: server crashed on singular Item_equal
+--echo #
+
+CREATE TABLE t1 (
+  a enum('p','r') NOT NULL DEFAULT 'r',
+  b int NOT NULL DEFAULT '0',
+  c char(32) NOT NULL,
+  d varchar(255) NOT NULL,
+  PRIMARY KEY (a, b), UNIQUE KEY idx(a, c)
+);
+INSERT INTO t1 VALUES ('r', 1, 'ad18832202b199728921807033a8a515', '001_cbr643');
+
+CREATE TABLE t2 (
+  a enum('p','r') NOT NULL DEFAULT 'r',
+  b int NOT NULL DEFAULT '0',
+  e datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  PRIMARY KEY (a, b, e)
+);
+INSERT INTO t2 VALUES ('r', 1, '2013-10-05 14:25:30');
+
+SELECT * FROM t1 AS t 
+  WHERE a='r' AND (c,b) NOT IN (SELECT c,b FROM t2 WHERE (c,b)=(t.c,t.b));
 
+DROP TABLE t1, t2;
 
 SET optimizer_switch= @@global.optimizer_switch;
 set @@tmp_table_size= @@global.tmp_table_size;