Fix for BUG#5837 - attempt 3.

  Call mark_as_null_row in join_read_const and join_read_system.


mysql-test/r/multi_update.result:
  Testcase for BUG#5837
mysql-test/t/multi_update.test:
  Testcase for BUG#5837
sql/table.h:
  Added comments

mysql-test/r/multi_update.result

@@ -399,3 +399,9 @@ select * from t2;
 c2_id	c2_p_id	c2_note	c2_active
 1	1	A Note	1
 drop table t1, t2;
+drop table if exists t2, t1;
+create table t1(aclid bigint not null primary key, status tinyint(1) not null ) type = innodb;
+create table t2(refid bigint not null primary key, aclid bigint, index idx_acl(aclid) )type = innodb;
+insert into t2 values(1,null);
+delete t2, t1 from t2 as a left join t1 as b on (a.aclid=b.aclid) where a.refid='1';
+drop table t1, t2;

mysql-test/t/multi_update.test

@@ -337,3 +337,12 @@ update t1 left join t2 on p_id = c2_p_id set c2_note = 'asdf-1' where p_id = 2;
 select * from t1;
 select * from t2;
 drop table t1, t2;
+
+# Test for BUG#5837 - delete with outer join and const tables
+drop table if exists t2, t1;
+create table t1(aclid bigint not null primary key, status tinyint(1) not null ) type = innodb;
+create table t2(refid bigint not null primary key, aclid bigint, index idx_acl(aclid) )type = innodb;
+insert into t2 values(1,null);
+delete t2, t1 from t2 as a left join t1 as b on (a.aclid=b.aclid) where a.refid='1';
+drop table t1, t2;
+

sql/sql_select.cc

@@ -4951,7 +4951,10 @@ join_read_system(JOIN_TAB *tab)
 	table->file->print_error(error,MYF(0));
 	return 1;
       }
-      table->null_row=1;			// This is ok.
+      if (tab->on_expr)
+        mark_as_null_row(tab->table);
+      else
+        table->null_row=1;			// Why do this for inner join?
       empty_record(table);			// Make empty record
       return -1;
     }
@@ -4981,7 +4984,10 @@ join_read_const(JOIN_TAB *tab)
     }
     if (error)
     {
-      table->null_row=1;
+      if (tab->on_expr)
+        mark_as_null_row(tab->table);
+      else
+        table->null_row=1;
       empty_record(table);
       if (error != HA_ERR_KEY_NOT_FOUND)
       {

sql/table.h

@@ -89,8 +89,14 @@ struct st_table {
   int current_lock;			/* Type of lock on table */
   enum tmp_table_type tmp_table;
   my_bool copy_blobs;			/* copy_blobs when storing */
-  my_bool null_row;			/* All columns are null */
-  my_bool maybe_null,outer_join;	/* Used with OUTER JOIN */
+  /*
+    Used in outer joins: if true, all columns are considered to have NULL
+    values, including columns declared as "not null".
+  */
+  my_bool null_row;
+  /* 0 or JOIN_TYPE_{LEFT|RIGHT}, same as TABLE_LIST::outer_join */
+  my_bool outer_join;
+  my_bool maybe_null;                   /* true if (outer_join != 0) */
   my_bool force_index;
   my_bool distinct,const_table,no_rows;
   my_bool key_read, bulk_insert;