merges r30536 from trunk into ruby_1_9_2.

--
* io.c (argf_next_argv): go advance when the next file cannot be
  read.  [ruby-core:34446]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@30574 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 16 insertions, 0 deletions

diff --git a/test/ruby/test_argf.rb b/test/ruby/test_argf.rb
index ffd5096789..678b811580 100644
--- a/test/ruby/test_argf.rb
+++ b/test/ruby/test_argf.rb
@@ -694,4 +694,20 @@ class TestArgf < Test::Unit::TestCase
       assert_equal([@t1.path, @t2.path, @t3.path].inspect, f.gets.chomp)
     end
   end
+
+  def test_unreadable
+    bug4274 = '[ruby-core:34446]'
+    paths = (1..2).map do
+      t = Tempfile.new("bug4274-")
+      path = t.path
+      t.close!
+      path
+    end
+    argf = ARGF.class.new(*paths)
+    paths.each do |path|
+      e = assert_raise(Errno::ENOENT) {argf.gets}
+      assert_match(/- #{Regexp.quote(path)}\z/, e.message)
+    end
+    assert_nil(argf.gets, bug4274)
+  end
 end