Detailed description of changes:
r3590 | marko | 2008-12-18 15:33:36 +0200 (Thu, 18 Dec 2008) | 11 lines
branches/5.1: When converting a record to MySQL format, copy the default
column values for columns that are SQL NULL.  This addresses failures in
row-based replication (Bug #39648).

row_prebuilt_t: Add default_rec, for the default values of the columns in
MySQL format.

row_sel_store_mysql_rec(): Use prebuilt->default_rec instead of
padding columns.

rb://64 approved by Heikki Tuuri