[LocalPod] Fixed clean paths.

Closes CocoaPods#519
Closes CocoaPods#568

CHANGELOG.md

@@ -3,6 +3,10 @@
 [CocoaPods](https://github.com/CocoaPods/CocoaPods/compare/0.15.0...master)
 
 ###### Bug fixes
+
+- Fixed an issue that lead to empty directories for Pods.
+  [#519](https://github.com/CocoaPods/CocoaPods/issues/519)
+  [#568](https://github.com/CocoaPods/CocoaPods/issues/568)
 - Fixed a crash related to the RubyGems version informative.
   [#570](https://github.com/CocoaPods/CocoaPods/issues/570)
 

lib/cocoapods/local_pod.rb

@@ -163,12 +163,14 @@ def clean!
     #
     # @return [Array<Strings>] The paths that can be deleted.
     #
+    # @note The Paths are downcased to prevent issues. See #568.
+    #
     def clean_paths
-      cached_used_paths = used_files
-      files = Dir.glob(root + "**/*", File::FNM_DOTMATCH)
+      used = used_files.map(&:downcase)
+      files = Dir.glob(root + "**/*", File::FNM_DOTMATCH).map(&:downcase)
 
       files.reject! do |candidate|
-        candidate.end_with?('.', '..') || cached_used_paths.any? do |path|
+        candidate.end_with?('.', '..') || used.any? do |path|
           path.include?(candidate) || candidate.include?(path)
         end
       end

spec/unit/local_pod_spec.rb

@@ -56,11 +56,11 @@
     end
 
     it "returns an expanded list the files to clean" do
-      clean_paths = @pod.clean_paths.map { |p| p.to_s.gsub(/.*Pods\/BananaLib/,'') }
+      clean_paths = @pod.clean_paths.map { |p| p.to_s.gsub(/.*pods\/bananalib/,'') }
       clean_paths.should.include "/.git/config"
       # * There are some hidden files on Travis
       # * The submodule of the repo (libPusher) can be ignore, to reduce noise of this test
-      clean_files_without_hidden = clean_paths.reject { |p| p.to_s.include?('/.') || p.to_s.include?('libPusher') }
+      clean_files_without_hidden = clean_paths.reject { |p| p.to_s.include?('/.') || p.to_s.include?('libpusher') }
       clean_files_without_hidden.should == %W[ /sub-dir /sub-dir/sub-dir-2 /sub-dir/sub-dir-2/somefile.txt ]
     end
 
@@ -208,8 +208,9 @@ def assert_array_equals(expected, computed)
        /StoreKit/StoreKit_Prefix.pch
        /UIKit/UIKit_Prefix.pch
      ]
-     computed = @pod.clean_paths.each{ |p| p.gsub!(@pod.root.to_s, '') }
-     assert_array_equals(expected, computed)
+     root = @pod.root.to_s.downcase
+     computed = @pod.clean_paths.each{ |p| p.gsub!(root, '') }
+     assert_array_equals(expected.map(&:downcase), computed)
     end
 
     it "resolves the used files" do