From e165cb0ab2931067e1e6a15a0811b4bdd5d861b6 Mon Sep 17 00:00:00 2001
From: Toks <tttoksss@gmail.com>
Date: Sat, 15 Aug 2015 17:12:00 -0400
Subject: [PATCH] fixes #2491

---
 app/logical/downloads/rewrite_strategies/base.rb  | 15 ++++++++++-----
 .../downloads/rewrite_strategies/tumblr.rb        | 15 ++++++++++++---
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/app/logical/downloads/rewrite_strategies/base.rb b/app/logical/downloads/rewrite_strategies/base.rb
index b1d8cd365..bd17fc0ce 100644
--- a/app/logical/downloads/rewrite_strategies/base.rb
+++ b/app/logical/downloads/rewrite_strategies/base.rb
@@ -14,16 +14,21 @@ module Downloads
       end
 
     protected
-      def http_exists?(url, headers)
-        exists = false
+      def http_head_request(url, headers)
         uri = URI.parse(url)
         Net::HTTP.start(uri.host, uri.port) do |http|
           http.request_head(uri.request_uri, headers) do |res|
-            if res.is_a?(Net::HTTPSuccess)
-              exists = true
-            end
+            return res
           end
         end
+      end
+
+      def http_exists?(url, headers)
+        exists = false
+        res = http_head_request(url, headers)
+        if res.is_a?(Net::HTTPSuccess)
+          exists = true
+        end
         exists
       end
     end
diff --git a/app/logical/downloads/rewrite_strategies/tumblr.rb b/app/logical/downloads/rewrite_strategies/tumblr.rb
index 7ea3c8296..9771fc7be 100644
--- a/app/logical/downloads/rewrite_strategies/tumblr.rb
+++ b/app/logical/downloads/rewrite_strategies/tumblr.rb
@@ -12,13 +12,22 @@ module Downloads
 
     protected
       def rewrite_thumbnails(url, headers)
-        if url =~ %r{^https?://.+\.tumblr\.com/(?:\w+/)?(?:tumblr_)?(\w+_)(\d+)\..+$}
+        if url =~ %r{^https?://.+\.tumblr\.com/(?:\w+/)?(?:tumblr_)?(\w+_)(\d+)(\..+)$}
           match = $1
           given_size = $2
+          file_ext = $3
 
           big_1280_url = url.sub(match + given_size, match + "1280")
-          if http_exists?(big_1280_url, headers)
-            return [big_1280_url, headers]
+          if file_ext == ".gif"
+            res = http_head_request(big_1280_url, headers)
+            # Sometimes the 1280 version of a gif is actually a static jpeg. We don't want that so we only use the 1280 version if it really is a gif.
+            if res.is_a?(Net::HTTPSuccess) && res["content-type"] == "image/gif"
+              return [big_1280_url, headers]
+            end
+          else
+            if http_exists?(big_1280_url, headers)
+              return [big_1280_url, headers]
+            end
           end
         end