BUG#5390 - problems with merge tables

Problem #1: INSERT...SELECT, Version for 4.1.
INSERT ... SELECT with the same table on both sides (hidden
below a MERGE table) does now work by buffering the select result.
The duplicate detection works now after open_and_lock_tables() 
on the locks.
I did not find a test case that failed without the change in
sql_update.cc. I made the change anyway as it should in theory
fix a possible MERGE table problem with multi-table update.


libmysqld/ha_blackhole.cc:
  BUG#5390 - problems with merge tables
  No idea, how the symlink change made it into my patch.
mysql-test/r/create.result:
  BUG#5390 - problems with merge tables
  Removed a duplicate test.
mysql-test/r/merge.result:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Added test results.
mysql-test/t/create.test:
  BUG#5390 - problems with merge tables
  Removed a duplicate test.
mysql-test/t/merge.test:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Added tests.
sql/lock.cc:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Added a new function to find a duplicate lock in a list of tables.
sql/mysql_priv.h:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Added a declaration for the new function.
sql/sql_parse.cc:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Changed the duplicate tables detection for INSERT ... SELECT
  to use the new function, which does also work for MERGE tables.
sql/sql_update.cc:
  BUG#5390 - problems with merge tables
  Problem #1: INSERT...SELECT, Version for 4.1.
  Changed the duplicate tables detection for UPDATE
  to use the new function, which does also work for MERGE tables.

1 files changed, 6 insertions, 5 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index fbca542dc24..90de630da60 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -2897,16 +2897,17 @@ unsent_create_error:
     if (unit->select_limit_cnt < select_lex->select_limit)
       unit->select_limit_cnt= HA_POS_ERROR;		// No limit
 
-    if (find_real_table_in_list(tables->next, tables->db, tables->real_name))
+    if ((res= open_and_lock_tables(thd, tables)))
+      break;
+
+    insert_table= tables->table;
+    /* MERGE sub-tables can only be detected after open. */
+    if (mysql_lock_have_duplicate(thd, insert_table, tables->next))
     {
       /* Using same table for INSERT and SELECT */
       select_lex->options |= OPTION_BUFFER_RESULT;
     }
 
-    if ((res= open_and_lock_tables(thd, tables)))
-      break;
-      
-    insert_table= tables->table;
     /* Skip first table, which is the table we are inserting in */
     select_lex->table_list.first= (byte*) first_local_table->next;
     tables= (TABLE_LIST *) select_lex->table_list.first;