Manual merge of mysql-5.1-bugteam to mysql-trunk-merge.

Conflicts:

Text conflict in configure.in
Text conflict in dbug/dbug.c
Text conflict in mysql-test/r/ps.result
Text conflict in mysql-test/t/ps.test
Text conflict in sql/CMakeLists.txt
Text conflict in sql/ha_ndbcluster.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/sql_plugin.cc
Text conflict in sql/sql_table.cc

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 41737b33fb6..a4c7d665b8a 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -1337,6 +1337,16 @@ int multi_update::prepare(List<Item> &not_used_values,
     {
       table->read_set= &table->def_read_set;
       bitmap_union(table->read_set, &table->tmp_set);
+      /*
+        If a timestamp field settable on UPDATE is present then to avoid wrong
+        update force the table handler to retrieve write-only fields to be able
+        to compare records and detect data change.
+        */
+      if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ &&
+          table->timestamp_field &&
+          (table->timestamp_field_type == TIMESTAMP_AUTO_SET_ON_UPDATE ||
+           table->timestamp_field_type == TIMESTAMP_AUTO_SET_ON_BOTH))
+        bitmap_union(table->read_set, table->write_set);
     }
   }