Fix a message bug.

test/file_message_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:test/test.dart';
 import 'package:source_span/source_span.dart';
 import 'package:source_span/src/colors.dart' as colors;
 
 main() {
   var file;
@@ skipping 41 matching lines @@
            ^"""));
   });
 
   test("works for a point span at the end of the file", () {
     expect(file.location(38).pointSpan().message("oh no"), equals("""
 line 3, column 12 of foo.dart: oh no
 zip zap zop
            ^"""));
   });
 
+  test("works for a point span at the end of the file with no trailing newline",
+      () {
+    file = new SourceFile("zip zap zop");
+    expect(file.location(11).pointSpan().message("oh no"), equals("""
+line 1, column 12: oh no
+zip zap zop
+           ^"""));
+  });
+
   test("works for a point span in an empty file", () {
     expect(new SourceFile("").location(0).pointSpan().message("oh no"),
         equals("""
 line 1, column 1: oh no
 
 ^"""));
   });
 
   test("works for a single-line file without a newline", () {
     expect(new SourceFile("foo bar").span(0, 7).message("oh no"),
@@ skipping 19 matching lines @@
     });
 
     test("uses the given color if it's passed", () {
       expect(file.span(4, 7).message("oh no", color: colors.YELLOW), equals("""
 line 1, column 5 of foo.dart: oh no
 foo ${colors.YELLOW}bar${colors.NONE} baz
     ${colors.YELLOW}^^^${colors.NONE}"""));
     });
   });
 }