diff --git a/mysql-test/r/constraints.result b/mysql-test/r/constraints.result
index 3b41e291e0f..7cd8053c21b 100644
--- a/mysql-test/r/constraints.result
+++ b/mysql-test/r/constraints.result
@@ -14,3 +14,16 @@ drop table t1;
 create table t1 (a int null);
 insert into t1 values (1),(NULL);
 drop table t1;
+create table t1 (a int null);
+alter table t1 add constraint constraint_1 unique (a);
+alter table t1 add constraint unique key_1(a);
+alter table t1 add constraint constraint_2 unique key_2(a);
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` int(11) default NULL,
+  UNIQUE KEY `constraint_1` (`a`),
+  UNIQUE KEY `key_1` (`a`),
+  UNIQUE KEY `key_2` (`a`)
+) TYPE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;
diff --git a/mysql-test/r/multi_update.result b/mysql-test/r/multi_update.result
index b0d597f238a..f6a96eb94a0 100644
--- a/mysql-test/r/multi_update.result
+++ b/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;
diff --git a/mysql-test/t/constraints.test b/mysql-test/t/constraints.test
index cc796e0abd2..dbc34a0dff1 100644
--- a/mysql-test/t/constraints.test
+++ b/mysql-test/t/constraints.test
@@ -21,3 +21,9 @@ drop table t1;
 create table t1 (a int null);
 insert into t1 values (1),(NULL);
 drop table t1;
+create table t1 (a int null);
+alter table t1 add constraint constraint_1 unique (a);
+alter table t1 add constraint unique key_1(a);
+alter table t1 add constraint constraint_2 unique key_2(a);
+show create table t1;
+drop table t1;
diff --git a/mysql-test/t/multi_update.test b/mysql-test/t/multi_update.test
index b3c742e0b30..0886b957ca7 100644
--- a/mysql-test/t/multi_update.test
+++ b/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;
diff --git a/mysql-test/t/rpl000001-slave.opt b/mysql-test/t/rpl000001-slave.opt
new file mode 100644
index 00000000000..627becdbfb5
--- /dev/null
+++ b/mysql-test/t/rpl000001-slave.opt
@@ -0,0 +1 @@
+--innodb
diff --git a/sql/item.cc b/sql/item.cc
index 5f9a9d4a657..a39805dd24a 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -601,8 +601,7 @@ int Item_param::save_in_field(Field *field, bool no_conversions)
 {
   THD *thd= current_thd;
 
-  if (thd->command == COM_PREPARE)
-    return -1;
+  DBUG_ASSERT(thd->command == COM_EXECUTE);
   
   if (null_value)
     return (int) set_field_to_null(field);   
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 7715ab01044..2399bf8d353 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -672,8 +672,6 @@ static bool mysql_test_select_fields(PREP_STMT *stmt, TABLE_LIST *tables,
     fix_tables_pointers(thd->lex->all_selects_list);
     if (!result && !(result= new select_send()))
     {
-      delete select_lex->having;
-      delete select_lex->where;
       send_error(thd, ER_OUT_OF_RESOURCES);
       DBUG_RETURN(1);
     }
@@ -681,10 +679,10 @@ static bool mysql_test_select_fields(PREP_STMT *stmt, TABLE_LIST *tables,
     JOIN *join= new JOIN(thd, fields, select_options, result);
     thd->used_tables= 0;	// Updated by setup_fields  
 
-  if (join->prepare(&select_lex->ref_pointer_array, tables, 
-		    wild_num, conds, og_num, order, group, having, proc, 
-                    select_lex, unit))
-    DBUG_RETURN(1);
+    if (join->prepare(&select_lex->ref_pointer_array, tables, 
+                      wild_num, conds, og_num, order, group, having, proc, 
+                      select_lex, unit))
+      DBUG_RETURN(1);
     if (send_prep_stmt(stmt, fields.elements) ||
         thd->protocol_simple.send_fields(&fields, 0) ||
 #ifndef EMBEDDED_LIBRARY
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 55f5b28fc78..3cf52c29a8c 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1692,10 +1692,6 @@ mysql_select(THD *thd, Item ***rref_pointer_array,
 err:
   if (free_join)
   {
-    JOIN *curr_join= (join->need_tmp&&join->tmp_join?
-		      (join->tmp_join->error=join->error,join->tmp_join):
-		      join);
-
     thd->proc_info="end";
     err= join->cleanup();
     if (thd->net.report_error)
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index cd08e702cd5..7e7a8976924 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -636,7 +636,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 
 %type <simple_string>
 	remember_name remember_end opt_ident opt_db text_or_password
-	opt_escape
+	opt_escape opt_constraint
 
 %type <string>
 	text_string opt_gconcat_separator
@@ -670,7 +670,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 	ident_list ident_list_arg
 
 %type <key_type>
-	key_type opt_unique_or_fulltext
+	key_type opt_unique_or_fulltext constraint_key_type
 
 %type <key_alg>
 	key_alg opt_btree_or_rtree
@@ -2144,6 +2144,13 @@ key_def:
 	    lex->key_list.push_back(new Key($1,$2, $3, lex->col_list));
 	    lex->col_list.empty();		/* Alloced by sql_alloc */
 	  }
+	| opt_constraint constraint_key_type opt_ident key_alg '(' key_list ')'
+	  {
+	    LEX *lex=Lex;
+	    const char *key_name= $3 ? $3:$1;
+	    lex->key_list.push_back(new Key($2, key_name, $4, lex->col_list));
+	    lex->col_list.empty();		/* Alloced by sql_alloc */
+	  }
 	| opt_constraint FOREIGN KEY_SYM opt_ident '(' key_list ')' references
 	  {
 	    LEX *lex=Lex;
@@ -2167,8 +2174,8 @@ check_constraint:
 	;
 
 opt_constraint:
-	/* empty */
-	| CONSTRAINT opt_ident;
+	/* empty */		{ $$=(char*) 0; }
+	| CONSTRAINT opt_ident	{ $$=$2; };
 
 field_spec:
 	field_ident
@@ -2530,14 +2537,16 @@ delete_option:
 	| SET DEFAULT    { $$= (int) foreign_key::FK_OPTION_DEFAULT;  };
 
 key_type:
-	opt_constraint PRIMARY_SYM KEY_SYM  { $$= Key::PRIMARY; }
-	| key_or_index			    { $$= Key::MULTIPLE; }
+	key_or_index			    { $$= Key::MULTIPLE; }
 	| FULLTEXT_SYM			    { $$= Key::FULLTEXT; }
 	| FULLTEXT_SYM key_or_index	    { $$= Key::FULLTEXT; }
 	| SPATIAL_SYM			    { $$= Key::SPATIAL; }
-	| SPATIAL_SYM key_or_index	    { $$= Key::SPATIAL; }
-	| opt_constraint UNIQUE_SYM	    { $$= Key::UNIQUE; }
-	| opt_constraint UNIQUE_SYM key_or_index { $$= Key::UNIQUE; };
+	| SPATIAL_SYM key_or_index	    { $$= Key::SPATIAL; };
+
+constraint_key_type:
+	PRIMARY_SYM KEY_SYM  { $$= Key::PRIMARY; }
+	| UNIQUE_SYM	    { $$= Key::UNIQUE; }
+	| UNIQUE_SYM key_or_index { $$= Key::UNIQUE; };
 
 key_or_index:
 	KEY_SYM {}
diff --git a/sql/uniques.cc b/sql/uniques.cc
index f289fd11f5b..02146426782 100644
--- a/sql/uniques.cc
+++ b/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;