Limit calls to Dir.chdir in Rake::Application

This reduces "conflicting chdir during another chdir block" warnings
when calling `Rake::Application#run` inside a `Dir.chdir` block.

Author: jonathanhefner

lib/rake/application.rb

@@ -269,18 +269,11 @@ def has_chain?(exception) # :nodoc:
     end
     private :has_chain?
 
-    # True if one of the files in RAKEFILES is in the current directory.
-    # If a match is found, it is copied into @rakefile.
-    def have_rakefile # :nodoc:
-      @rakefiles.each do |fn|
-        if File.exist?(fn)
-          others = FileList.glob(fn, File::FNM_CASEFOLD)
-          return others.size == 1 ? others.first : fn
-        elsif fn == ""
-          return fn
-        end
+    # Returns first filename from @rakefiles that exists in the specified dir.
+    def have_rakefile(dir = Dir.pwd) # :nodoc:
+      Dir.chdir(dir) do
+        Dir.glob(@rakefiles.map { |name| escape_for_glob(name) }).first || @rakefiles.find(&:empty?)
       end
-      return nil
     end
 
     # True if we are outputting to TTY, false otherwise
@@ -669,45 +662,37 @@ def rake_require(file_name, paths=$LOAD_PATH, loaded=$") # :nodoc:
     end
 
     def find_rakefile_location # :nodoc:
-      here = Dir.pwd
-      until (fn = have_rakefile)
-        Dir.chdir("..")
-        return nil if Dir.pwd == here || options.nosearch
-        here = Dir.pwd
+      previous_dir, current_dir = nil, original_dir
+      until (rakefile = have_rakefile(current_dir)) || current_dir == previous_dir
+        break if options.nosearch
+        previous_dir, current_dir = current_dir, File.expand_path("..", current_dir)
       end
-      [fn, here]
-    ensure
-      Dir.chdir(Rake.original_dir)
+      [rakefile, current_dir] if rakefile
     end
 
-    def print_rakefile_directory(location) # :nodoc:
-      $stderr.puts "(in #{Dir.pwd})" unless
-        options.silent or original_dir == location
+    def print_rakefile_directory # :nodoc:
+      $stderr.puts "(in #{@rakefile_dir})" unless
+        options.silent || original_dir == @rakefile_dir
     end
 
     def raw_load_rakefile # :nodoc:
-      rakefile, location = find_rakefile_location
+      @rakefile, @rakefile_dir = find_rakefile_location
+
       if (!options.ignore_system) &&
-          (options.load_system || rakefile.nil?) &&
+          (options.load_system || @rakefile.nil?) &&
           system_dir && File.directory?(system_dir)
-        print_rakefile_directory(location)
-        glob("#{system_dir}/*.rake") do |name|
-          add_import name
-        end
+        print_rakefile_directory
+        add_globbed_imports(system_dir, "*.rake")
       else
-        fail "No Rakefile found (looking for: #{@rakefiles.join(', ')})" if
-          rakefile.nil?
-        @rakefile = rakefile
-        Dir.chdir(location)
-        print_rakefile_directory(location)
-        Rake.load_rakefile(File.expand_path(@rakefile)) if
-          @rakefile && @rakefile != ""
-        options.rakelib.each do |rlib|
-          glob("#{rlib}/*.rake") do |name|
-            add_import name
-          end
+        fail "No Rakefile found (looking for: #{@rakefiles.join(", ")})" if @rakefile.nil?
+        Dir.chdir(@rakefile_dir) unless @rakefile_dir == Dir.pwd
+        print_rakefile_directory
+        Rake.load_rakefile(File.expand_path(@rakefile, @rakefile_dir)) unless @rakefile.empty?
+        options.rakelib.each do |rakelib|
+          add_globbed_imports(File.expand_path(rakelib, @rakefile_dir), "*.rake")
         end
       end
+
       load_imports
     end
 
@@ -716,6 +701,11 @@ def glob(path, &block) # :nodoc:
     end
     private :glob
 
+    def escape_for_glob(pattern)
+      pattern.tr("\\", "/").gsub(/[*?\[\]{}]/, "\\\\" + '\0')
+    end
+    private :escape_for_glob
+
     # The directory path containing the system wide rakefiles.
     def system_dir # :nodoc:
       @system_dir ||=
@@ -771,6 +761,14 @@ def add_import(fn) # :nodoc:
       @pending_imports << fn
     end
 
+    # Globs "#{directory}/#{pattern}", and adds the results to the list
+    # of files to be imported.
+    def add_globbed_imports(directory, pattern) # :nodoc:
+      Dir.glob("#{escape_for_glob(directory).chomp("/")}/#{pattern}") do |path|
+        add_import path
+      end
+    end
+
     # Load the pending list of imported files.
     def load_imports # :nodoc:
       while fn = @pending_imports.shift

test/test_rake_application.rb

@@ -240,6 +240,7 @@ def test_load_rakefile_doesnt_print_rakefile_directory_from_same_dir
   def test_load_rakefile_from_subdir
     rakefile_unittest
     Dir.chdir "subdir"
+    @app = Rake::Application.new
 
     @app.instance_eval do
       handle_options []
@@ -248,7 +249,6 @@ def test_load_rakefile_from_subdir
     end
 
     assert_equal "rakefile", @app.rakefile.downcase
-    assert_equal @tempdir, Dir.pwd
   end
 
   def test_load_rakefile_prints_rakefile_directory_from_subdir
@@ -439,6 +439,19 @@ def test_good_run
     assert_equal "DEFAULT\n", out
   end
 
+  def test_runs_in_rakefile_directory_from_subdir
+    rakefile_unittest
+    Dir.chdir "subdir"
+    @app = Rake::Application.new
+
+    pwd = nil
+    @app.define_task(Rake::Task, "default") { pwd = Dir.pwd }
+
+    @app.run %w[--silent]
+
+    assert_equal @tempdir, pwd
+  end
+
   def test_display_task_run
     ran = false
     @app.last_description = "COMMENT"