ext/objspace: Check fptr before trying to dump FILE object fd

Patch by Scott Francis. Closes GH-562.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45308 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Tue Mar 11 06:54:00 2014  Scott Francis  <scott.francis@shopify.com>
+
+	* ext/objspace/objspace_dump.c: Check fptr before trying to dump RFILE
+	  object fd. [GH-562]
+
+	* test/objspace/test_objspace.rb: add test
+
 Tue Mar 11 02:04:36 2014  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* vm_dump.c (rb_vm_bugreport): show vm maps on FreeBSD.

ext/objspace/objspace_dump.c

@@ -230,7 +230,8 @@ dump_object(VALUE obj, struct dump_config *dc)
 
       case T_FILE:
 	fptr = RFILE(obj)->fptr;
-	dump_append(dc, ", \"fd\":%d", fptr->fd);
+	if (fptr)
+	    dump_append(dc, ", \"fd\":%d", fptr->fd);
 	break;
 
       case T_ZOMBIE:

test/objspace/test_objspace.rb

@@ -266,4 +266,15 @@ class TestObjSpace < Test::Unit::TestCase
       File.unlink(output)
     end
   end
+
+  def test_dump_uninitialized_file
+    assert_in_out_err(%[-robjspace], <<-RUBY) do |output, error|
+      puts ObjectSpace.dump(File.allocate)
+    RUBY
+      assert_equal [], error
+      json = JSON.load(output.join)
+      assert_equal "FILE", json["type"]
+      assert_nil json["fd"]
+    end
+  end
 end