--- redmine-3.4.3/app/helpers/repositories_helper.rb	2017-10-15 21:59:56.000000000 +0200
+++ redmine/app/helpers/repositories_helper.rb	2017-11-18 09:17:26.865403482 +0100
@@ -278,7 +278,7 @@
         :href  => block_given? ? yield(commit.scmid) : commit.scmid
       }
     end
-    heads.sort! { |head1, head2| head1.to_s <=> head2.to_s }
+    heads.sort_by! { |head| [if head.is_default then 0 else 1 end, head.to_s] }
     space = nil  
     heads.each do |head|
       if commits_by_scmid.include? head.scmid