Merge branch...

Merge branch 'rd-fix-bug-when-authenticating-user-for-repo-with-size-check-enabled-ce' into 'master'

Backport of gitlab-org/gitlab-ee!6848

See merge request gitlab-org/gitlab-ce!21096

lib/gitlab/git/repository.rb

@@ -382,7 +382,7 @@ module Gitlab
       end
 
       def new_blobs(newrev)
-        return [] if newrev == ::Gitlab::Git::BLANK_SHA
+        return [] if newrev.blank? || newrev == ::Gitlab::Git::BLANK_SHA
 
         strong_memoize("new_blobs_#{newrev}") do
           wrapped_gitaly_errors do