Merge branch 'compare-commits-on-nil-refs' into 'master'

Compare returns an empty collection of commits on nil refs

See merge request !114

CHANGELOG

 v 10.4.5
   - Write .gitattributes in binary mode to prevent Rails from converting ASCII-8BIT to UTF-8
+  - Compare returns an empty collection of commits on nil refs
 v 10.4.4
   - Lazy load compare commits

lib/gitlab_git/compare.rb

@@ -6,7 +6,10 @@ module Gitlab
       def initialize(repository, base, head)
         @repository = repository
-        return unless base && head
+        unless base && head
+          @commits = []
+          return
+        end
         @base = Gitlab::Git::Commit.find(repository, base.try(:strip))
         @head = Gitlab::Git::Commit.find(repository, head.try(:strip))

spec/compare_spec.rb

@@ -32,6 +32,12 @@ describe Gitlab::Git::Compare do
       it { is_expected.to be_empty }
     end
+
+    context 'providing nil as base ref or head ref' do
+      let(:compare) { Gitlab::Git::Compare.new(repository, nil, nil) }
+
+      it { is_expected.to be_empty }
+    end
   end
   describe :diffs do