io.c: path name conversion at ARGF

* io.c (argf_next_argv): the standard conversion to path name
  should take place.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60154 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

io.c

@@ -136,6 +136,8 @@ off_t __syscall(quad_t number, ...);
 #ifdef _WIN32
 #undef open
 #define open	rb_w32_uopen
+#undef rename
+#define rename(f, t)	rb_w32_urename((f), (t))
 #endif
 
 VALUE rb_cIO;
@@ -8249,8 +8251,8 @@ argf_next_argv(VALUE argf)
       retry:
 	if (RARRAY_LEN(ARGF.argv) > 0) {
 	    VALUE filename = rb_ary_shift(ARGF.argv);
-	    StringValueCStr(filename);
+	    FilePathValue(filename);
-	    ARGF.filename = rb_str_encode_ospath(filename);
+	    ARGF.filename = filename;
 	    fn = StringValueCStr(filename);
 	    if (RSTRING_LEN(filename) == 1 && fn[0] == '-') {
 		ARGF.current_file = rb_stdin;

test/ruby/test_argf.rb

@@ -316,6 +316,34 @@ class TestArgf < Test::Unit::TestCase
     }
   end
 
+  def test_inplace_to_path
+    base = "argf-test"
+    name = "#{@tmpdir}/#{base}"
+    File.write(name, "foo")
+    stdout = $stdout
+    argf = ARGF.class.new(Struct.new(:to_path).new(name))
+    begin
+      result = argf.gets
+    ensure
+      $stdout = stdout
+      argf.close
+    end
+    assert_equal("foo", result)
+  end
+
+  def test_inplace_ascii_incompatible_path
+    base = "argf-\u{30c6 30b9 30c8}"
+    name = "#{@tmpdir}/#{base}"
+    File.write(name, "foo")
+    stdout = $stdout
+    argf = ARGF.class.new(name.encode(Encoding::UTF_16LE))
+    assert_raise(Encoding::CompatibilityError) do
+      argf.gets
+    end
+  ensure
+    $stdout = stdout
+  end
+
   def test_encoding
     ruby('-e', "#{<<~"{#"}\n#{<<~'};'}", @t1.path, @t2.path, @t3.path) do |f|
       {#