From 9cbb009b2ea4bffbf450d1b540d04387fbe9865b Mon Sep 17 00:00:00 2001
From: Gleb Shchepa <gshchepa@mysql.com>
Date: Fri, 14 May 2010 15:36:27 +0400
Subject: [PATCH] Bug #53450: Crash / assertion "virtual int            
 ha_myisam::index_first(uchar*)") at assert.c:81

Single-table DELETE crash/assertion similar to single-table
UPDATE bug 14272.

Same resolution as for the bug 14272:
Don't run index scan when we should use quick select.
This could cause failures because there are table handlers (like federated)
that support quick select scanning but do not support index scanning.


mysql-test/r/delete.result:
  Test case for bug #53450.
mysql-test/t/delete.test:
  Test case for bug #53450.
sql/sql_delete.cc:
  Bug #53450: Crash / assertion "virtual int
              ha_myisam::index_first(uchar*)") at assert.c:81

  The mysql_delete function has been modified to not to use
  init_read_record_idx instead of init_read_record for the
  quick select.
---
 mysql-test/r/delete.result |  9 +++++++++
 mysql-test/t/delete.test   | 12 ++++++++++++
 sql/sql_delete.cc          |  2 +-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/delete.result b/mysql-test/r/delete.result
index 77b2071494d..36025cbfb35 100644
--- a/mysql-test/r/delete.result
+++ b/mysql-test/r/delete.result
@@ -349,4 +349,13 @@ END |
 DELETE IGNORE FROM t1;
 ERROR HY000: Can't update table 't1' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
 DROP TABLE t1;
+#
+# Bug #53450: Crash/assertion
+#    "virtual int ha_myisam::index_first(uchar*)") at assert.c:81
+#
+CREATE TABLE t1 (a INT,    b INT,    c INT,
+INDEX(a), INDEX(b), INDEX(c));
+INSERT INTO t1 VALUES (1,2,3), (4,5,6), (7,8,9);
+DELETE FROM t1 WHERE a = 10 OR b = 20 ORDER BY c LIMIT 1;
+DROP TABLE t1;
 End of 5.1 tests
diff --git a/mysql-test/t/delete.test b/mysql-test/t/delete.test
index 7bbc470137a..5a0e86568f3 100644
--- a/mysql-test/t/delete.test
+++ b/mysql-test/t/delete.test
@@ -374,5 +374,17 @@ DELETE IGNORE FROM t1;
 
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #53450: Crash/assertion
+--echo #    "virtual int ha_myisam::index_first(uchar*)") at assert.c:81
+--echo #
+
+CREATE TABLE t1 (a INT,    b INT,    c INT,
+                 INDEX(a), INDEX(b), INDEX(c));
+INSERT INTO t1 VALUES (1,2,3), (4,5,6), (7,8,9);
+
+DELETE FROM t1 WHERE a = 10 OR b = 20 ORDER BY c LIMIT 1;
+
+DROP TABLE t1;
 
 --echo End of 5.1 tests
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index cc29b6f1b6b..07421ca55a6 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -266,7 +266,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     free_underlaid_joins(thd, select_lex);
     DBUG_RETURN(TRUE);
   }
-  if (usable_index==MAX_KEY)
+  if (usable_index==MAX_KEY || (select && select->quick))
     init_read_record(&info, thd, table, select, 1, 1, FALSE);
   else
     init_read_record_idx(&info, thd, table, 1, usable_index);