Bug#41370: TIMESTAMP field does not accepts NULL from FROM_UNIXTIME()

When storing a NULL to a TIMESTAMP NOT NULL DEFAULT ...,
NULL returned from some functions threw a 'cannot be NULL error.'

NULL-returns now correctly result in the timestamp-field being
assigned its default value.

mysql-test/r/type_timestamp.result:
  Show that for TIMESTAMP NOT NULL DEFAULT, NULL function returns
  set default now.
mysql-test/t/type_timestamp.test:
  Show that for TIMESTAMP NOT NULL DEFAULT, NULL function returns
  set default now.
sql/item.cc:
  When storing a returned NULL (from a time- or date-related
  function), make sure to apply NULL-means-DEFAULT magic where
  applicable.

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 2a89c86cd88..977c5f0b7c0 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -321,7 +321,7 @@ int Item::save_time_in_field(Field *field)
 {
   MYSQL_TIME ltime;
   if (get_time(&ltime))
-    return set_field_to_null(field);
+    return set_field_to_null_with_conversions(field, 0);
   field->set_notnull();
   return field->store_time(&ltime, MYSQL_TIMESTAMP_TIME);
 }
@@ -331,7 +331,7 @@ int Item::save_date_in_field(Field *field)
 {
   MYSQL_TIME ltime;
   if (get_date(&ltime, TIME_FUZZY_DATE))
-    return set_field_to_null(field);
+    return set_field_to_null_with_conversions(field, 0);
   field->set_notnull();
   return field->store_time(&ltime, MYSQL_TIMESTAMP_DATETIME);
 }