JRUBY-5572: Fix Dir.foreach for jar files

src/org/jruby/RubyDir.java

@@ -100,7 +100,7 @@ private final void checkDir() {
     }
 
     private void update() {
-        if (snapshot == null || dir.lastModified() > lastModified) {
+        if (snapshot == null || dir.exists() && dir.lastModified() > lastModified) {
             lastModified = dir.lastModified();
             List<String> snapshotList = new ArrayList<String>();
             snapshotList.add(".");

test/test_dir.rb

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 require 'test/unit'
 require 'rbconfig'
 
@@ -162,6 +163,19 @@ def test_glob_with_magic_inside_jar_file
     end
   end
 
+  def test_foreach_works_in_jar_file
+    jar_file = File.expand_path('../jar_with_relative_require1.jar', __FILE__)
+    jar_path = "file:#{jar_file}!/test"
+    dir = Dir.new(jar_path)
+    assert dir.entries.include?('require_relative1.rb'), "#{jar_path} does not contain require_relative1.rb: #{dir.entries.inspect}"
+    entries = []
+    dir.each {|d| entries << d}
+    assert entries.include?('require_relative1.rb'), "#{jar_path} does not contain require_relative1.rb: #{entries.inspect}"
+    entries = []
+    Dir.foreach(jar_path) {|d| entries << d}
+    assert entries.include?('require_relative1.rb'), "#{jar_path} does not contain require_relative1.rb: #{entries.inspect}"
+  end
+
   def jar_file_with_spaces
     require 'test/dir with spaces/test_jar.jar'
     require 'inside_jar'