Merge bk-internal.mysql.com:/home/bk/mysql-4.1

into mysql.com:/home/dlenev/src/mysql-4.1-ryan

1 files changed, 17 insertions, 14 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index e8441c05609..34cad1b062d 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -4142,12 +4142,7 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
     }
     else if (default_value->type() == Item::NULL_ITEM)
     {
-      /*
-        TIMESTAMP type should be able to distingush non-specified default
-        value and default value NULL later.
-      */
-      if (type != FIELD_TYPE_TIMESTAMP)
-        default_value= 0;
+      default_value= 0;
       if ((type_modifier & (NOT_NULL_FLAG | AUTO_INCREMENT_FLAG)) ==
 	  NOT_NULL_FLAG)
       {
@@ -4357,19 +4352,27 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
       else
         new_field->unireg_check= (on_update_value?Field::TIMESTAMP_UN_FIELD:
                                                   Field::NONE);
-
-      if (default_value->type() == Item::NULL_ITEM)
-        new_field->def= 0;
     }
     else
     {
-      /* 
-        We are setting TIMESTAMP_OLD_FIELD here only temporary, we will 
-        replace this value by TIMESTAMP_DNUN_FIELD or NONE later when 
+      /*
+        If we have default TIMESTAMP NOT NULL column without explicit DEFAULT
+        or ON UPDATE values then for the sake of compatiblity we should treat
+        this column as having DEFAULT NOW() ON UPDATE NOW() (when we don't
+        have another TIMESTAMP column with auto-set option before this one)
+        or DEFAULT 0 (in other cases).
+        So here we are setting TIMESTAMP_OLD_FIELD only temporary, and will
+        replace this value by TIMESTAMP_DNUN_FIELD or NONE later when
         information about all TIMESTAMP fields in table will be availiable.
+
+        If we have TIMESTAMP NULL column without explicit DEFAULT value
+        we treat it as having DEFAULT NULL attribute.
       */
-      new_field->unireg_check= on_update_value?Field::TIMESTAMP_UN_FIELD:
-                                               Field::TIMESTAMP_OLD_FIELD;
+      new_field->unireg_check= on_update_value ?
+                               Field::TIMESTAMP_UN_FIELD :
+                               (new_field->flags & NOT_NULL_FLAG ?
+                                Field::TIMESTAMP_OLD_FIELD:
+                                Field::NONE);
     }
     break;
   case FIELD_TYPE_DATE:				// Old date type