BUG#10974 - No error message if merge table based on union of innodb, memory

Fixed confusing error message from the storage engine when
it fails to open underlying table. The error message is issued
when a table is _opened_ (not when it is created).

myisammrg/myrg_open.c

@@ -89,7 +89,10 @@ MYRG_INFO *myrg_open(const char *name, int mode, int handle_locking)
     else
       fn_format(buff, buff, "", "", 0);
     if (!(isam=mi_open(buff,mode,(handle_locking?HA_OPEN_WAIT_IF_LOCKED:0))))
+    {
+      my_errno= HA_ERR_WRONG_MRG_TABLE_DEF;
       goto err;
+    }
     if (!m_info)                                /* First file */
     {
       key_parts=isam->s->base.key_parts;

mysql-test/r/merge.result

@@ -178,9 +178,9 @@ t3	CREATE TABLE `t3` (
 ) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
 create table t4 (a int not null, b char(10), key(a)) engine=MERGE UNION=(t1,t2);
 select * from t4;
-ERROR HY000: Can't open file: 't4.MRG' (errno: 143)
+ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exists
 alter table t4 add column c int;
-ERROR HY000: Can't open file: 't4.MRG' (errno: 143)
+ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exists
 create database mysqltest;
 create table mysqltest.t6 (a int not null primary key auto_increment, message char(20));
 create table t5 (a int not null, b char(20), key(a)) engine=MERGE UNION=(test.t1,mysqltest.t6);
@@ -766,3 +766,12 @@ Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
 test.t2	check	status	OK
 drop table t1, t2, t3;
+CREATE TABLE t1(a INT) ENGINE=MEMORY;
+CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t1);
+SELECT * FROM t2;
+ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exists
+DROP TABLE t1, t2;
+CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t3);
+SELECT * FROM t2;
+ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exists
+DROP TABLE t2;

mysql-test/r/repair.result

@@ -31,7 +31,7 @@ create table t1 engine=myisam SELECT 1,"table 1";
 flush tables;
 repair table t1;
 Table	Op	Msg_type	Msg_text
-test.t1	repair	error	Can't open file: 't1.MYI' (errno: 130)
+test.t1	repair	error	Got error 130 from storage engine
 repair table t1 use_frm;
 Table	Op	Msg_type	Msg_text
 test.t1	repair	warning	Number of rows changed from 0 to 1

mysql-test/t/merge.test

@@ -47,9 +47,9 @@ show create table t3;
 
 # The following should give errors
 create table t4 (a int not null, b char(10), key(a)) engine=MERGE UNION=(t1,t2);
---error 1016
+--error 1168
 select * from t4;
---error 1016
+--error 1168
 alter table t4 add column c int;
 
 #
@@ -376,4 +376,18 @@ select * from t3;
 check table t1, t2;
 drop table t1, t2, t3;
 
+#
+# BUG#10974 - No error message if merge table based on union of innodb,
+# memory
+#
+CREATE TABLE t1(a INT) ENGINE=MEMORY;
+CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t1);
+--error 1168
+SELECT * FROM t2;
+DROP TABLE t1, t2;
+CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t3);
+--error 1168
+SELECT * FROM t2;
+DROP TABLE t2;
+
 # End of 4.1 tests

sql/share/english/errmsg.txt

@@ -184,7 +184,7 @@ character-set=latin1
 "INSERT DELAYED can't be used with table '%-.64s' because it is locked with LOCK TABLES",
 "Incorrect column name '%-.100s'",
 "The used storage engine can't index column '%-.64s'",
-"All tables in the MERGE table are not identically defined",
+"Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exists",
 "Can't write, because of unique constraint, to table '%-.64s'",
 "BLOB/TEXT column '%-.64s' used in key specification without a key length",
 "All parts of a PRIMARY KEY must be NOT NULL; if you need NULL in a key, use UNIQUE instead",

sql/table.cc

@@ -77,6 +77,7 @@ int openfrm(const char *name, const char *alias, uint db_stat, uint prgflag,
   my_string record;
   const char **int_array;
   bool	 use_hash, null_field_first;
+  bool   error_reported= FALSE;
   File	 file;
   Field  **field_ptr,*reg_field;
   KEY	 *keyinfo;
@@ -791,6 +792,11 @@ int openfrm(const char *name, const char *alias, uint db_stat, uint prgflag,
 	error= 1;
 	my_errno= ENOENT;
       }
+      else
+      {
+        outparam->file->print_error(err, MYF(0));
+        error_reported= TRUE;
+      }
       goto err_not_open; /* purecov: inspected */
     }
   }
@@ -812,7 +818,8 @@ int openfrm(const char *name, const char *alias, uint db_stat, uint prgflag,
  err_end:					/* Here when no file */
   delete crypted;
   *root_ptr= old_root;
-  frm_error(error, outparam, name, ME_ERROR + ME_WAITTANG, errarg);
+  if (!error_reported)
+    frm_error(error, outparam, name, ME_ERROR + ME_WAITTANG, errarg);
   delete outparam->file;
   outparam->file=0;				// For easyer errorchecking
   outparam->db_stat=0;