bk commit into 5.0 tree (svoj:1.2600) BUG#35274

[Sergey Vojtovich]

Below is the list of changes that have just been committed into a local
5.0 repository of svoj.  When svoj does a push these changes
will be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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ChangeSet@stripped, 2008-03-24 15:12:46+04:00, svoj@stripped +3 -0
  BUG#35274 - merge table doesn't need any base tables, gives
              error 124 when key accessed
  
  SELECT queries that use index against a merge table with empty
  underlying tables list may return with error "Got error 124 from
  storage engine".
  
  The problem was in wrong error being returned.

  myisammrg/myrg_queue.c@stripped, 2008-03-24 15:12:43+04:00, svoj@stripped +11 -1
    Return "end of file" error instead of "wrong index" error when
    we got a merge table with empty underlying tables list.

  mysql-test/r/merge.result@stripped, 2008-03-24 15:12:43+04:00, svoj@stripped +5 -0
    A test case for BUG#35274.

  mysql-test/t/merge.test@stripped, 2008-03-24 15:12:43+04:00, svoj@stripped +8 -0
    A test case for BUG#35274.

diff -Nrup a/myisammrg/myrg_queue.c b/myisammrg/myrg_queue.c
--- a/myisammrg/myrg_queue.c	2006-12-31 00:02:05 +04:00
+++ b/myisammrg/myrg_queue.c	2008-03-24 15:12:43 +04:00
@@ -65,7 +65,17 @@ int _myrg_init_queue(MYRG_INFO *info,int
     }
   }
   else
-    my_errno= error= HA_ERR_WRONG_INDEX;
+  {
+    /*
+      inx may be bigger than info->keys if there are no underlying tables
+      defined. In this case we should return empty result. As we check for
+      underlying tables conformance when we open a table, we may not enter
+      this branch with underlying table that has less keys than merge table
+      have.
+    */
+    DBUG_ASSERT(!info->open_tables);
+    error= my_errno= HA_ERR_END_OF_FILE;
+  }
   return error;
 }
 
diff -Nrup a/mysql-test/r/merge.result b/mysql-test/r/merge.result
--- a/mysql-test/r/merge.result	2008-03-14 19:38:20 +04:00
+++ b/mysql-test/r/merge.result	2008-03-24 15:12:43 +04:00
@@ -940,4 +940,9 @@ m1	CREATE TABLE `m1` (
   `a` int(11) default NULL
 ) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1
 DROP TABLE t1, m1;
+CREATE TABLE t1(a INT, KEY(a)) ENGINE=merge;
+SELECT MAX(a) FROM t1;
+MAX(a)
+NULL
+DROP TABLE t1;
 End of 5.0 tests
diff -Nrup a/mysql-test/t/merge.test b/mysql-test/t/merge.test
--- a/mysql-test/t/merge.test	2008-03-14 19:38:20 +04:00
+++ b/mysql-test/t/merge.test	2008-03-24 15:12:43 +04:00
@@ -556,4 +556,12 @@ ALTER TABLE m1 UNION=();
 SHOW CREATE TABLE m1;
 DROP TABLE t1, m1;
 
+#
+# BUG#35274 - merge table doesn't need any base tables, gives error 124 when
+#             key accessed
+#
+CREATE TABLE t1(a INT, KEY(a)) ENGINE=merge;
+SELECT MAX(a) FROM t1;
+DROP TABLE t1;
+
 --echo End of 5.0 tests