`am` strips extra path from pull reqs URLs such as "pull/42/files"

lib/hub/commands.rb

@@ -236,6 +236,8 @@ module Hub
       if url = args.find { |a| a =~ %r{^https?://(gist\.)?github\.com/} }
         idx = args.index(url)
         gist = $1 == 'gist.'
+        # strip extra path from "pull/42/files", "pull/42/commits"
+        url = url.sub(%r{(/pull/\d+)/\w*$}, '\1') unless gist
         ext = gist ? '.txt' : '.patch'
         url += ext unless File.extname(url) == ext
         patch_file = File.join(ENV['TMPDIR'], "#{gist ? 'gist-' : ''}#{File.basename(url)}")

test/hub_test.rb

@@ -360,6 +360,9 @@ class HubTest < Test::Unit::TestCase
       assert_commands "curl -#LA 'hub #{Hub::Version}' https://github.com/defunkt/hub/pull/55.patch -o /tmp/55.patch",
                       "git am --signoff /tmp/55.patch -p2",
                       "am --signoff https://github.com/defunkt/hub/pull/55 -p2"
+
+      cmd = Hub("am https://github.com/defunkt/hub/pull/55/files").command
+      assert_includes '/pull/55.patch', cmd
     end
   end