[Bug #19042] Fix Dir.glob brace with '/'

Dir.glob brace pattern with '/' after '**' does not match
paths in recursive expansion process.
We expand braces with '/' before expanding a recursive.

Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>

dir.c

@@ -2305,7 +2305,7 @@ glob_helper(
 #endif
             break;
           case BRACE:
-            if (!recursive) {
+            if (!recursive || strchr(p->str, '/')) {
                 brace = 1;
             }
             break;

test/ruby/test_dir.rb

@@ -259,6 +259,20 @@ class TestDir < Test::Unit::TestCase
     end
   end
 
+  def test_glob_recursive_with_brace
+    Dir.chdir(@root) do
+      bug19042 = '[ruby-core:110220] [Bug #19042]'
+      %w"c/dir_a c/dir_b c/dir_b/dir".each do |d|
+        Dir.mkdir(d)
+      end
+      expected = %w"c/dir_a/file c/dir_b/dir/file"
+      expected.each do |f|
+        File.write(f, "")
+      end
+      assert_equal(expected, Dir.glob("**/{dir_a,dir_b/dir}/file"), bug19042)
+    end
+  end
+
   def test_glob_order
     Dir.chdir(@root) do
       assert_equal(["#{@root}/a", "#{@root}/b"], Dir.glob("#{@root}/[ba]"))