From 45521bfd3e050fe680f05dd33a4a606d7ae6e871 Mon Sep 17 00:00:00 2001
From: PikachuEXE <pikachuexe@gmail.com>
Date: Thu, 18 Jun 2020 11:56:03 +0800
Subject: [PATCH] Fix handling of redirect response without Location header

---
 lib/fastimage.rb | 5 ++++-
 test/test.rb     | 7 +++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/fastimage.rb b/lib/fastimage.rb
index fe630c8..96c7222 100644
--- a/lib/fastimage.rb
+++ b/lib/fastimage.rb
@@ -296,7 +296,10 @@ def fetch_using_http_from_parsed_uri
       if res.is_a?(Net::HTTPRedirection) && @redirect_count < 4
         @redirect_count += 1
         begin
-          @parsed_uri = URI.join(@parsed_uri, escaped_location(res['Location']))
+          location = res['Location']
+          raise ImageFetchFailure if location.nil? || location.empty?
+
+          @parsed_uri = URI.join(@parsed_uri, escaped_location(location))
         rescue URI::InvalidURIError
         else
           fetch_using_http_from_parsed_uri
diff --git a/test/test.rb b/test/test.rb
index 6a4a5fc..3d3f9d3 100644
--- a/test/test.rb
+++ b/test/test.rb
@@ -300,6 +300,13 @@ def test_should_handle_permanent_redirect_with_encoded_url
     assert_equal GoodFixtures[GoodFixtures.keys.first][1], FastImage.size(TestUrl, :raise_on_failure=>true)
   end
 
+  def test_should_handle_permanent_redirect_with_missing_location
+    register_redirect(TestUrl, nil)
+    assert_raises(FastImage::ImageFetchFailure) do
+      FastImage.size(TestUrl, :raise_on_failure=>true)
+    end
+  end
+
   def register_redirect(from, to)
     resp = Net::HTTPMovedPermanently.new(1.0, 302, "Moved")
     resp['Location'] = to