fix(filters): make sure year is always at least 1

Resolves https://vikunja.sentry.io/share/issue/ef81451b0c7b43f1bff2d3a86ba393bb/
Resolves https://github.com/go-vikunja/app/issues/94#issuecomment-2351818484

pkg/models/task_collection_filter.go

@@ -276,6 +276,15 @@ func getValueForField(field reflect.StructField, rawValue string, loc *time.Loca
 			} else {
 				value, err = parseTimeFromUserInput(rawValue)
 			}
+			if err != nil {
+				return
+			}
+			// Mariadb does not support date values where the year is 0. To make this edge-case work,
+			// we're setting the year to 1 in that case.
+			tt := value.(time.Time)
+			if tt.Year() == 0 {
+				value = tt.AddDate(1, 0, 0)
+			}
 		}
 	case reflect.Slice:
 		// If this is a slice of pointers we're dealing with some property which is a relation

pkg/models/task_collection_filter_test.go

@@ -255,4 +255,12 @@ func TestParseFilter(t *testing.T) {
 		sevenDaysAgo := time.Now().Add(-7 * 24 * time.Hour)
 		assert.Equal(t, sevenDaysAgo.Unix(), result[0].value.(time.Time).Unix())
 	})
+	t.Run("date filter with 0000-01-01", func(t *testing.T) {
+		result, err := getTaskFiltersFromFilterString("due_date > 0000-01-01", "UTC")
+
+		require.NoError(t, err)
+		require.Len(t, result, 1)
+		date := result[0].value.(time.Time)
+		assert.Equal(t, 1, date.Year())
+	})
 }