[GR-32025] Guard against nil in match nodes when ** at start of pattern.

PullRequest: truffleruby/2722

Author: aardvark179

spec/ruby/core/dir/shared/glob.rb

@@ -205,6 +205,14 @@
     Dir.send(@method, '**/').sort.should == expected
   end
 
+  it "recursively matches any subdirectories except './' or '../' with '**/' from the base directory if that is specified" do
+    expected = %w[
+      nested/directory
+    ]
+
+    Dir.send(@method, '**/*ory', base: 'deeply').sort.should == expected
+  end
+
   ruby_version_is ''...'3.1' do
     it "recursively matches any subdirectories including ./ and ../ with '.**/'" do
       Dir.chdir("#{DirSpecs.mock_dir}/subdir_one") do

src/main/ruby/truffleruby/core/dir_glob.rb

@@ -181,7 +181,7 @@ def process_directory(matches, parent, entry, glob_base_dir)
           switched = @next.dup
           switched.separator = @separator
         else
-          @next.process_entry entry, true, matches, parent, glob_base_dir if glob_base_dir
+          @next.process_entry '', true, matches, parent, glob_base_dir if glob_base_dir
         end
 
         stack = [nil]