Resolve "Converting an empty text to date field results in '01/01/0001'"

backend/src/baserow/contrib/database/fields/field_types.py

@@ -323,18 +323,32 @@ class DateFieldType(FieldType):
         if from_field_type.type != self.type and connection.vendor == 'postgresql':
             sql_function = 'TO_DATE'
             sql_format = DATE_FORMAT[to_field.date_format]['sql']
+            sql_type = 'date'
 
             if to_field.date_include_time:
                 sql_function = 'TO_TIMESTAMP'
                 sql_format += ' ' + DATE_TIME_FORMAT[to_field.date_time_format]['sql']
+                sql_type = 'timestamp'
 
             return f"""
                 begin
-                    p_in = GREATEST(
-                        {sql_function}(p_in::text, 'FM{sql_format}'),
-                        '0001-01-01'::date
-                    );
-                exception when others then end;
+                    IF char_length(p_in::text) < 5 THEN
+                        p_in = null;
+                    ELSEIF p_in IS NULL THEN
+                        p_in = null;
+                    ELSE
+                        p_in = GREATEST(
+                            {sql_function}(p_in::text, 'FM{sql_format}'),
+                            '0001-01-01'::{sql_type}
+                        );
+                    END IF;
+                exception when others then
+                    begin
+                        p_in = GREATEST(p_in::{sql_type}, '0001-01-01'::{sql_type});
+                    exception when others then
+                        p_in = p_default;
+                    end;
+                end;
             """
 
         return super().get_alter_column_prepare_old_value(connection, from_field,

backend/src/baserow/contrib/database/migrations/0028_fix_negative_date.py

@@ -24,7 +24,6 @@ def forward(apps, schema_editor):
             )
 
 
-
 class Migration(migrations.Migration):
 
     dependencies = [

backend/tests/baserow/contrib/database/field/test_date_field_type.py

@@ -371,28 +371,74 @@ def test_negative_date_field_value(data_fixture):
     datetime_field = data_fixture.create_text_field(table=table)
 
     model = table.get_model()
+    model.objects.create(**{
+        f'field_{date_field.id}': '',
+        f'field_{datetime_field.id}': '',
+    })
+    model.objects.create(**{
+        f'field_{date_field.id}': 'INVALID',
+        f'field_{datetime_field.id}': 'INVALID',
+    })
+    model.objects.create(**{
+        f'field_{date_field.id}': ' ',
+        f'field_{datetime_field.id}': ' ',
+    })
+    model.objects.create(**{
+        f'field_{date_field.id}': '0',
+        f'field_{datetime_field.id}': '0',
+    })
     model.objects.create(**{
         f'field_{date_field.id}': '-0',
         f'field_{datetime_field.id}': '-0',
     })
+    model.objects.create(**{
+        f'field_{date_field.id}': '00000',
+        f'field_{datetime_field.id}': '00000',
+    })
+    model.objects.create(**{
+        f'field_{date_field.id}': None,
+        f'field_{datetime_field.id}': None,
+    })
     model.objects.create(**{
         f'field_{date_field.id}': '2010-02-03',
         f'field_{datetime_field.id}': '2010-02-03 12:30',
     })
+    model.objects.create(**{
+        f'field_{date_field.id}': '28/01/2012',
+        f'field_{datetime_field.id}': '28/01/2012 12:30',
+    })
 
-    date_field = FieldHandler().update_field(user, date_field, new_type_name='date')
-    datetime_field = FieldHandler().update_field(user, datetime_field,
-                                                 new_type_name='date',
-                                                 date_include_time=True)
+    date_field = FieldHandler().update_field(
+        user, date_field, new_type_name='date'
+    )
+    datetime_field = FieldHandler().update_field(
+        user, datetime_field, new_type_name='date', date_include_time=True
+    )
 
     model = table.get_model()
     results = model.objects.all()
 
-    assert getattr(results[0], f'field_{date_field.id}') == date(1, 1, 1)
-    assert getattr(results[0], f'field_{datetime_field.id}') == (
-        datetime(1, 1, 1, 0, 0, 0, tzinfo=timezone('utc'))
+    assert getattr(results[0], f'field_{date_field.id}') is None
+    assert getattr(results[0], f'field_{datetime_field.id}') is None
+    assert getattr(results[1], f'field_{date_field.id}') is None
+    assert getattr(results[1], f'field_{datetime_field.id}') is None
+    assert getattr(results[2], f'field_{date_field.id}') is None
+    assert getattr(results[2], f'field_{datetime_field.id}') is None
+    assert getattr(results[3], f'field_{date_field.id}') is None
+    assert getattr(results[3], f'field_{datetime_field.id}') is None
+    assert getattr(results[4], f'field_{date_field.id}') is None
+    assert getattr(results[4], f'field_{datetime_field.id}') is None
+    assert getattr(results[5], f'field_{date_field.id}') == date(1, 1, 1)
+    assert getattr(results[5], f'field_{datetime_field.id}') == (
+        datetime(1, 1, 1, tzinfo=timezone('utc'))
     )
-    assert getattr(results[1], f'field_{date_field.id}') == date(2010, 2, 3)
-    assert getattr(results[1], f'field_{datetime_field.id}') == (
+    assert getattr(results[6], f'field_{date_field.id}') is None
+    assert getattr(results[6], f'field_{datetime_field.id}') is None
+    assert getattr(results[7], f'field_{date_field.id}') == date(2010, 2, 3)
+    assert getattr(results[7], f'field_{datetime_field.id}') == (
         datetime(2010, 2, 3, 12, 30, 0, tzinfo=timezone('utc'))
     )
+    assert getattr(results[8], f'field_{date_field.id}') == date(2012, 1, 28)
+    assert getattr(results[8], f'field_{datetime_field.id}') == (
+        datetime(2012, 1, 28, 12, 30, 0, tzinfo=timezone('utc'))
+    )

changelog.md

@@ -18,6 +18,7 @@
   reconnect loop stops.
 * Fixed 100X backend web socket errors when refreshing the page.
 * Fixed SSRF bug in the file upload by URL by blocking urls to the private network.
+* Fixed bug where an invalid date could be converted to 0001-01-01.
 
 ## Released (2021-03-01)