Fix for bug #1980

mysql-test/r/multi_update.result

@@ -363,3 +363,30 @@ t2 rows after big delete	1900001
 select 't1 rows after big delete', count(*) from t1;
 t1 rows after big delete	count(*)
 t1 rows after big delete	1900001
+drop table t1,t2;
+set @ttype_save=@@table_type;
+set @@table_type=innodb;
+create table t1 ( c char(8) not null );
+insert into t1 values ('0'),('1'),('2'),('3'),('4'),('5'),('6'),('7'),('8'),('9');
+insert into t1 values ('A'),('B'),('C'),('D'),('E'),('F');
+alter table t1 add b char(8) not null;
+alter table t1 add a char(8) not null;
+alter table t1 add primary key (a,b,c);
+update t1 set a=c, b=c;
+create table t2 like t1;
+insert into t2 select * from t1;
+delete t1,t2 from t2,t1 where t1.a<'B' and t2.b=t1.b;
+drop table t1,t2;
+set @@table_type=bdb;
+create table t1 ( c char(8) not null );
+insert into t1 values ('0'),('1'),('2'),('3'),('4'),('5'),('6'),('7'),('8'),('9');
+insert into t1 values ('A'),('B'),('C'),('D'),('E'),('F');
+alter table t1 add b char(8) not null;
+alter table t1 add a char(8) not null;
+alter table t1 add primary key (a,b,c);
+update t1 set a=c, b=c;
+create table t2 like t1;
+insert into t2 select * from t1;
+delete t1,t2 from t2,t1 where t1.a<'B' and t2.b=t1.b;
+set @@table_type=@ttype_save;
+drop table t1,t2;

mysql-test/t/multi_update.test

@@ -309,4 +309,50 @@ delete t1,t2 from t1,t2 where t1.b=t2.a and t1.a < 100*1000;
 select 't2 rows after big delete', count(*) from t2;
 select 't1 rows after big delete', count(*) from t1;
 
-#drop table t1,t2;
+drop table t1,t2;
+
+#
+# Test for bug #1980.
+#
+set @ttype_save=@@table_type;
+
+--disable_warnings
+set @@table_type=innodb;
+create table t1 ( c char(8) not null );
+--enable_warnings
+
+insert into t1 values ('0'),('1'),('2'),('3'),('4'),('5'),('6'),('7'),('8'),('9');
+insert into t1 values ('A'),('B'),('C'),('D'),('E'),('F');
+
+alter table t1 add b char(8) not null;
+alter table t1 add a char(8) not null;
+alter table t1 add primary key (a,b,c);
+update t1 set a=c, b=c;
+
+create table t2 like t1;
+insert into t2 select * from t1;
+
+delete t1,t2 from t2,t1 where t1.a<'B' and t2.b=t1.b;
+
+drop table t1,t2;
+
+--disable_warnings
+set @@table_type=bdb;
+create table t1 ( c char(8) not null );
+--enable_warnings
+
+insert into t1 values ('0'),('1'),('2'),('3'),('4'),('5'),('6'),('7'),('8'),('9');
+insert into t1 values ('A'),('B'),('C'),('D'),('E'),('F');
+
+alter table t1 add b char(8) not null;
+alter table t1 add a char(8) not null;
+alter table t1 add primary key (a,b,c);
+update t1 set a=c, b=c;
+
+create table t2 like t1;
+insert into t2 select * from t1;
+
+delete t1,t2 from t2,t1 where t1.a<'B' and t2.b=t1.b;
+
+set @@table_type=@ttype_save;
+drop table t1,t2;

sql/uniques.cc

@@ -37,14 +37,20 @@
 
 int unique_write_to_file(gptr key, element_count count, Unique *unique)
 {
+  /*
+    Use unique->size (size of element stored in the tree) and not 
+    unique->tree.size_of_element. The latter is different from unique->size 
+    when tree implementation chooses to store pointer to key in TREE_ELEMENT
+    (instead of storing the element itself there)
+  */
   return my_b_write(&unique->file, (byte*) key,
-		    unique->tree.size_of_element) ? 1 : 0;
+		    unique->size) ? 1 : 0;
 }
 
 int unique_write_to_ptrs(gptr key, element_count count, Unique *unique)
 {
-  memcpy(unique->record_pointers, key, unique->tree.size_of_element);
-  unique->record_pointers+=unique->tree.size_of_element;
+  memcpy(unique->record_pointers, key, unique->size);
+  unique->record_pointers+=unique->size;
   return 0;
 }
 
@@ -133,7 +139,7 @@ bool Unique::get(TABLE *table)
   sort_param.max_rows= elements;
   sort_param.sort_form=table;
   sort_param.rec_length= sort_param.sort_length=sort_param.ref_length=
-    tree.size_of_element;
+    size;
   sort_param.keys= max_in_memory_size / sort_param.sort_length;
   sort_param.not_killable=1;