bk commit into 5.0 tree (mhansson:1.2597) BUG#34529

[mhansson]

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ChangeSet@stripped, 2008-03-19 14:25:19+01:00, mhansson@riffraff.(none) +3 -0
  Bug#34529: Crash on complex Falcon I_S select after ALTER .. PARTITION BY
    
  When swapping out heap I_S tables to disk, this is done after plan refinement.
  Thus, READ_RECORD::file will still point to the (deleted) heap handler at start
  of execution. This causes segmentation fault if join buffering is used and the 
  query is a star query where the result is found to be empty before accessing
  some table. In this case that table has not been initialized (i.e. had its 
  READ_RECORD re-initialized) before the cleanup routine tries to close the handler.
  Fixed by updating READ_RECORD::file when changing handler.

  mysql-test/r/information_schema.result@stripped, 2008-03-19 14:25:17+01:00, mhansson@riffraff.(none) +10 -0
    Bug#34529: Test result.

  mysql-test/t/information_schema.test@stripped, 2008-03-19 14:25:17+01:00, mhansson@riffraff.(none) +21 -0
    Bug#34529: Test case.

  sql/sql_show.cc@stripped, 2008-03-19 14:25:17+01:00, mhansson@riffraff.(none) +2 -0
    Bug#34529: The fix.

diff -Nrup a/mysql-test/r/information_schema.result b/mysql-test/r/information_schema.result
--- a/mysql-test/r/information_schema.result	2007-10-29 11:45:33 +01:00
+++ b/mysql-test/r/information_schema.result	2008-03-19 14:25:17 +01:00
@@ -1422,3 +1422,13 @@ show fields from information_schema.tabl
 ERROR 42S02: Unknown table 'table_names' in information_schema
 show keys from information_schema.table_names;
 ERROR 42S02: Unknown table 'table_names' in information_schema
+USE information_schema;
+SET max_heap_table_size = 16384;
+CREATE TABLE test.t1( a INT );
+SELECT *
+FROM tables ta
+JOIN collations co ON ( co.collation_name = ta.table_catalog )
+JOIN character_sets cs ON ( cs.character_set_name = ta.table_catalog );
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT	COLLATION_NAME	CHARACTER_SET_NAME	ID	IS_DEFAULT	IS_COMPILED	SORTLEN	CHARACTER_SET_NAME	DEFAULT_COLLATE_NAME	DESCRIPTION	MAXLEN
+DROP TABLE test.t1;
+SET max_heap_table_size = DEFAULT;
diff -Nrup a/mysql-test/t/information_schema.test b/mysql-test/t/information_schema.test
--- a/mysql-test/t/information_schema.test	2007-10-29 11:45:33 +01:00
+++ b/mysql-test/t/information_schema.test	2008-03-19 14:25:17 +01:00
@@ -1118,3 +1118,24 @@ show fields from information_schema.tabl
 --error 1109
 show keys from information_schema.table_names;
 
+#
+# Bug#34529: Crash on complex Falcon I_S select after ALTER .. PARTITION BY
+#
+USE information_schema;
+SET max_heap_table_size = 16384;
+
+CREATE TABLE test.t1( a INT );
+
+# What we need to create here is a bit of a corner case:
+# We need a star query with information_schema tables, where the first
+# branch of the star join produces zero rows, so that reading of the 
+# second branch never happens. At the same time we have to make sure
+# that data for at least the last table is swapped from MEMORY/HEAP to 
+# MyISAM. This and only this triggers the bug.
+SELECT *
+FROM tables ta
+JOIN collations co ON ( co.collation_name = ta.table_catalog )
+JOIN character_sets cs ON ( cs.character_set_name = ta.table_catalog );
+
+DROP TABLE test.t1;
+SET max_heap_table_size = DEFAULT;
diff -Nrup a/sql/sql_show.cc b/sql/sql_show.cc
--- a/sql/sql_show.cc	2007-12-17 09:12:06 +01:00
+++ b/sql/sql_show.cc	2008-03-19 14:25:17 +01:00
@@ -4073,9 +4073,11 @@ bool get_schema_tables_result(JOIN *join
       {
         result= 1;
         join->error= 1;
+        tab->read_record.file= table_list->table->file;
         table_list->schema_table_state= executed_place;
         break;
       }
+      tab->read_record.file= table_list->table->file;
       table_list->schema_table_state= executed_place;
     }
   }