Also consider when acc_count is more than count

Author: José Valim

lib/elixir/lib/stream/reducers.ex

@@ -25,7 +25,7 @@ defmodule Stream.Reducers do
     end
 
     after_fun = fn {acc_buffer, acc_count} ->
-      if leftover == :discard or acc_count == 0 or (step > count and count == acc_count) do
+      if leftover == :discard or acc_count == 0 or (step > count and acc_count >= count) do
         {:cont, []}
       else
         {:cont, :lists.reverse(acc_buffer, Enum.take(leftover, count - acc_count)), []}

lib/elixir/test/elixir/enum_test.exs

@@ -75,6 +75,7 @@ defmodule EnumTest do
     assert Enum.chunk_every([1, 2, 3, 4, 5, 6], 2, 3, []) == [[1, 2], [4, 5]]
     assert Enum.chunk_every([1, 2, 3, 4, 5, 6, 7], 2, 3, []) == [[1, 2], [4, 5], [7]]
     assert Enum.chunk_every([1, 2, 3, 4, 5, 6, 7], 2, 3, [8]) == [[1, 2], [4, 5], [7, 8]]
+    assert Enum.chunk_every([1, 2, 3, 4, 5, 6, 7], 2, 4, []) == [[1, 2], [5, 6]]
   end
 
   test "chunk_by/2" do