Handle tilde in Path.expand/1,2 properly

Author: lexmag

lib/elixir/lib/path.ex

@@ -585,11 +585,23 @@ defmodule Path do
 
   defp expand_home(type) do
     case IO.chardata_to_string(type) do
-      "~" <> rest -> System.user_home! <> rest
+      "~" <> rest -> resolve_home(rest)
       rest        -> rest
     end
   end
 
+  defp resolve_home(""), do: System.user_home!
+
+  defp resolve_home(rest) do
+    case {rest, major_os_type} do
+      {"\\" <> _, :win32} ->
+        System.user_home! <> rest
+      {"/" <> _, _} ->
+        System.user_home! <> rest
+      _ -> rest
+    end
+  end
+
   defp normalize(path), do: normalize(split(path), [])
 
   defp normalize([".."|t], ["/"|_] = acc) do

lib/elixir/test/elixir/path_test.exs

@@ -112,6 +112,7 @@ defmodule PathTest do
     assert Path.expand("~/file", "whatever") == Path.join(home, "file")
     assert Path.expand("file", Path.expand("~")) == Path.expand("~/file")
     assert Path.expand("file", "~") == Path.join(home, "file")
+    assert Path.expand("~file") == Path.join(System.cwd!, "file")
   end
 
   test :expand_path do