Ensure Calendar.ISO enforces date limits

Author: lexmag

lib/elixir/lib/calendar/iso.ex

@@ -122,13 +122,13 @@ defmodule Calendar.ISO do
   def date_to_iso_days_days(1970, 1, 1) do
     719528
   end
-  def date_to_iso_days_days(year, month, day) do
+  def date_to_iso_days_days(year, month, day) when year <= 9999 do
     :calendar.date_to_gregorian_days(year, month, day)
   end
 
   # Converts count of days since 0000-01-01 to {year, month, day} tuple.
   @doc false
-  def date_from_iso_days_days(days) do
+  def date_from_iso_days_days(days) when days <= 3652424 do
     :calendar.gregorian_days_to_date(days)
   end
 

lib/elixir/test/elixir/calendar_test.exs

@@ -66,6 +66,15 @@ defmodule DateTest do
            {:ok, Calendar.Holocene.date(12000, 01, 01)}
   end
 
+  test "add/2" do
+    assert_raise FunctionClauseError, fn ->
+      Date.add(~D[0000-01-01], 3652425)
+    end
+    assert_raise FunctionClauseError, fn ->
+      Date.add(~D[0000-01-01], -1)
+    end
+  end
+
   test "diff/2" do
     assert Date.diff(~D[2000-01-31], ~D[2000-01-01]) == 30
     assert Date.diff(~D[2000-01-01], ~D[2000-01-31]) == -30