Set default options outside the raw_log method

The raw_log method is meant to become the Gitaly RPC boundary. By
setting the defaults before doing the RPC we keep the RPC
implementation simpler. We also sidestep the unfortunate subtleties of
what happens when options[:limit] is not set, or nil.

lib/gitlab/git/repository.rb

@@ -297,6 +297,21 @@ module Gitlab
       #   )
       #
       def log(options)
+        default_options = {
+          limit: 10,
+          offset: 0,
+          path: nil,
+          follow: false,
+          skip_merges: false,
+          disable_walk: false,
+          after: nil,
+          before: nil
+        }
+
+        options = default_options.merge(options)
+        options[:limit] ||= 0
+        options[:offset] ||= 0
+
         raw_log(options).map { |c| Commit.decorate(c) }
       end
 
@@ -710,20 +725,6 @@ module Gitlab
       end
 
       def raw_log(options)
-        default_options = {
-          limit: 10,
-          offset: 0,
-          path: nil,
-          follow: false,
-          skip_merges: false,
-          disable_walk: false,
-          after: nil,
-          before: nil
-        }
-
-        options = default_options.merge(options)
-        options[:limit] ||= 0
-        options[:offset] ||= 0
         actual_ref = options[:ref] || root_ref
         begin
           sha = sha_from_ref(actual_ref)