From 35984510e0a3c192e66571b5bd1ce80f281ad0e8 Mon Sep 17 00:00:00 2001
From: Lars Kanis <lars@greiz-reinsdorf.de>
Date: Sun, 25 Feb 2018 21:33:33 +0100
Subject: [PATCH] Fix path checks for case insensitive filesystem

On Windows paths are case insensitive. That means that path
comparisons must be done case insensitive.

Different lower / upper case characters can happen, when RbConfig::TOPDIR
or GEM_HOME are set to a path of different case.

This bug was introduced in commit 666ef793c .
It stood out in this nokogiri issue:
https://github.com/sparklemotion/nokogiri/issues/1726
---
 lib/rubygems/package.rb           | 10 +++++++++-
 test/rubygems/test_gem_package.rb | 15 +++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/rubygems/package.rb b/lib/rubygems/package.rb
index b924122827..c6368d69a8 100644
--- a/lib/rubygems/package.rb
+++ b/lib/rubygems/package.rb
@@ -429,6 +429,14 @@ def install_location filename, destination_dir # :nodoc:
     destination
   end
 
+  def normalize_path(pathname)
+    if Gem.win_platform?
+      pathname.downcase
+    else
+      pathname
+    end
+  end
+
   def mkdir_p_safe mkdir, mkdir_options, destination_dir, file_name
     destination_dir = realpath File.expand_path(destination_dir)
     parts = mkdir.split(File::SEPARATOR)
@@ -437,7 +445,7 @@ def mkdir_p_safe mkdir, mkdir_options, destination_dir, file_name
       path = File.expand_path(path + File::SEPARATOR + basename)
       lstat = File.lstat path rescue nil
       if !lstat || !lstat.directory?
-        unless path.start_with? destination_dir and (FileUtils.mkdir path, mkdir_options rescue false)
+        unless normalize_path(path).start_with? normalize_path(destination_dir) and (FileUtils.mkdir path, mkdir_options rescue false)
           raise Gem::Package::PathError.new(file_name, destination_dir)
         end
       end
diff --git a/test/rubygems/test_gem_package.rb b/test/rubygems/test_gem_package.rb
index d1664cf285..b9169b16c9 100644
--- a/test/rubygems/test_gem_package.rb
+++ b/test/rubygems/test_gem_package.rb
@@ -524,6 +524,21 @@ def test_extract_tar_gz_dot_file
     assert_path_exists extracted
   end
 
+  if Gem.win_platform?
+    def test_extract_tar_gz_case_insensitive
+      package = Gem::Package.new @gem
+
+      tgz_io = util_tar_gz do |tar|
+        tar.add_file 'foo/file.rb', 0644 do |io| io.write 'hi' end
+      end
+
+      package.extract_tar_gz tgz_io, @destination.upcase
+
+      extracted = File.join @destination, 'foo/file.rb'
+      assert_path_exists extracted
+    end
+  end
+
   def test_install_location
     package = Gem::Package.new @gem