Merge branch 'git-hooks-initial-push' into 'master'

Fix git hook validation on initial push to master branch.

Addresses #305.

See merge request !434

CHANGELOG-EE

-v 7.12 (Unreleased)
+v 7.13 (Unrelease)
+  - Fix git hook validation on initial push to master branch.
+
+v 7.12
   - Fix error when viewing merge request with a commit that includes "Closes #<issue id>".
   - Enhance LDAP group synchronization to check also for member attributes that only contain "uid=<username>"
   - Enhance LDAP group synchronization to check also for submember attributes

lib/gitlab/git_access.rb

@@ -182,13 +182,18 @@ module Gitlab
           return build_status_object(false, "You can not delete tag")
         end
       else
-        # Check commit messages unless its branch removal
-        if git_hook.commit_validation? && !Gitlab::Git.blank_ref?(newrev)
-          if Gitlab::Git.blank_ref?(oldrev)
-            oldrev = project.default_branch
+        return build_status_object(true) unless git_hook.commit_validation?
+        return build_status_object(true) if Gitlab::Git.blank_ref?(newrev)
+
+        oldrev = project.default_branch if Gitlab::Git.blank_ref?(oldrev)
+
+        commits = 
+          if oldrev
+            project.repository.commits_between(oldrev, newrev)
+          else
+            project.repository.commits(newrev)
           end
 
-          commits = project.repository.commits_between(oldrev, newrev)
         commits.each do |commit|
           if git_hook.commit_message_regex.present?
             unless commit.safe_message =~ Regexp.new(git_hook.commit_message_regex)
@@ -239,7 +244,6 @@ module Gitlab
           end
         end
       end
-      end
 
       build_status_object(true)
     end