LAST_INSERT_ID() should not be set if we couldn't generate an auto_increment id.

mysql-test/r/auto_increment.result:
  Update after auto_increment fix
mysql-test/t/auto_increment.test:
  Another fix for LAST_INSERT_ID()
sql/handler.cc:
  Another fix for LAST_INSERT_ID()
sql/sql_class.h:
  Another fix for LAST_INSERT_ID()

mysql-test/r/auto_increment.result

@@ -111,11 +111,16 @@ insert into t1 set i = null;
 select last_insert_id();
 last_insert_id()
 255
+insert into t1 set i = 254;
+ERROR 23000: Duplicate entry '254' for key 1
+select last_insert_id();
+last_insert_id()
+255
 insert into t1 set i = null;
 ERROR 23000: Duplicate entry '255' for key 1
 select last_insert_id();
 last_insert_id()
-255
+0
 drop table t1;
 create table t1 (i tinyint unsigned not null auto_increment, key (i));
 insert into t1 set i = 254;

mysql-test/t/auto_increment.test

@@ -80,6 +80,9 @@ insert into t1 set i = 254;
 insert into t1 set i = null;
 select last_insert_id();
 --error 1062
+insert into t1 set i = 254;
+select last_insert_id();
+--error 1062
 insert into t1 set i = null;
 select last_insert_id();
 drop table t1;
@@ -100,5 +103,6 @@ select last_insert_id();
 --error 1062
 insert into t1 values (NULL, 10);
 select last_insert_id();
+
 drop table t1;
 

sql/handler.cc

@@ -709,6 +709,8 @@ void handler::update_auto_increment()
     nr=get_auto_increment();
   if (!table->next_number_field->store(nr))
     thd->insert_id((ulonglong) nr);
+  else
+    thd->insert_id(table->next_number_field->val_int());
   auto_increment_column_changed=1;
   DBUG_VOID_RETURN;
 }

sql/sql_class.h

@@ -503,8 +503,23 @@ class THD :public ilink
 #ifdef SIGNAL_WITH_VIO_CLOSE
   Vio* active_vio;
 #endif  
-  ulonglong  next_insert_id,last_insert_id,current_insert_id,
-             limit_found_rows;
+  /*
+    next_insert_id is set on SET INSERT_ID= #. This is used as the next
+    generated auto_increment value in handler.cc
+  */
+  ulonglong  next_insert_id;
+  /*
+    The insert_id used for the last statement or set by SET LAST_INSERT_ID=#
+    or SELECT LAST_INSERT_ID(#).  Used for binary log and returned by
+    LAST_INSERT_ID()
+  */
+  ulonglong  last_insert_id;
+  /*
+    Set to the first value that LAST_INSERT_ID() returned for the last
+    statement.  When this is set, last_insert_id_used is set to true.
+  */
+  ulonglong  current_insert_id;
+  ulonglong  limit_found_rows;
   ha_rows    select_limit, offset_limit, cuted_fields,
              sent_row_count, examined_row_count;
   table_map  used_tables;