#At file:///home/vn/work/mysql/workspaces-bazaar/shared_repository_directory/mysql-5.1-bug38338/
2680 Narayanan V 2008-08-17
Bug#38338
Fix the write_record function to record auto increment
values in a consistent way.
modified:
sql/sql_insert.cc
per-file messages:
sql/sql_insert.cc
The algorithm for the write_record function
in sql_insert.cc is (more emphasis given to
the parts that deal with the autogenerated values)
1) If a write fails
1.1) save the autogenerated value to avoid
thd->insert_id_for_cur_row to become 0.
1.2) <logic to handle INSERT ON DUPLICATE KEY
UPDATE and REPLACE>
2) record the first successful insert id.
explanation of the failure
--------------------------
As long as 1.1) was executed 2) worked fine.
1.1) was always executed when REPLACE worked
with the last row update optimization, but
in cases where 1.1) was not executed 2)
would fail and would result in the autogenerated
value not being saved.
solution
--------
repeat a check for thd->insert_id_for_cur_row
being zero similar to 1.1) before 2) and ensure
that the correct value is saved.
=== modified file 'sql/sql_insert.cc'
--- a/sql/sql_insert.cc 2008-07-11 18:51:10 +0000
+++ b/sql/sql_insert.cc 2008-08-17 17:12:39 +0000
@@ -1545,6 +1545,17 @@ int write_record(THD *thd, TABLE *table,
}
}
}
+
+ /*
+ If more than one iteration of the above while loop is done, from the second
+ one the row being inserted will have an explicit value in the autoinc field,
+ which was set at the first call of handler::update_auto_increment(). This
+ value is saved to avoid thd->insert_id_for_cur_row becoming 0. Use this saved
+ autoinc value.
+ */
+ if (table->file->insert_id_for_cur_row <= 0)
+ table->file->insert_id_for_cur_row= insert_id_for_cur_row;
+
thd->record_first_successful_insert_id_in_cur_stmt(table->file->insert_id_for_cur_row);
/*
Restore column maps if they where replaced during an duplicate key
