BUG#21726: Incorrect result with multiple invocations of LAST_INSERT_ID.

Note: bug#21726 does not directly apply to 4.1, as it doesn't have stored
procedures.  However, 4.1 had some bugs that were fixed in 5.0 by the
patch for bug#21726, and this patch is a backport of those fixes.
Namely, in 4.1 it fixes:

  - LAST_INSERT_ID(expr) didn't return value of expr (4.1 specific).

  - LAST_INSERT_ID() could return the value generated by current
    statement if the call happens after the generation, like in

      CREATE TABLE t1 (i INT AUTO_INCREMENT PRIMARY KEY, j INT);
      INSERT INTO t1 VALUES (NULL, 0), (NULL, LAST_INSERT_ID());

  - Redundant binary log LAST_INSERT_ID_EVENTs could be generated.

1 files changed, 4 insertions, 8 deletions

diff --git a/sql/sql_load.cc b/sql/sql_load.cc
index 4e6c458cc43..48862506729 100644
--- a/sql/sql_load.cc
+++ b/sql/sql_load.cc
@@ -466,10 +466,8 @@ read_fixed_length(THD *thd,COPY_INFO &info,TABLE *table,List<Item> &fields,
     if (write_record(table,&info))
       DBUG_RETURN(1);
     /*
-      If auto_increment values are used, save the first one
-       for LAST_INSERT_ID() and for the binary/update log.
-       We can't use insert_id() as we don't want to touch the
-       last_insert_id_used flag.
+      If auto_increment values are used, save the first one for
+      LAST_INSERT_ID() and for the binary/update log.
     */
     if (!id && thd->insert_id_used)
       id= thd->last_insert_id;
@@ -572,10 +570,8 @@ read_sep_field(THD *thd,COPY_INFO &info,TABLE *table,
     if (write_record(table,&info))
       DBUG_RETURN(1);
     /*
-      If auto_increment values are used, save the first one
-       for LAST_INSERT_ID() and for the binary/update log.
-       We can't use insert_id() as we don't want to touch the
-       last_insert_id_used flag.
+      If auto_increment values are used, save the first one for
+      LAST_INSERT_ID() and for the binary/update log.
     */
     if (!id && thd->insert_id_used)
       id= thd->last_insert_id;