NestedHash optimization.

Commit optimization.
Fix pull without previous commit.

lib/eternity/commit.rb

@@ -47,6 +47,7 @@ def base_delta
     end
 
     def fast_forward?(commit)
+      return true unless commit
       return commit.nil? if base.nil?
       base.id == commit.id || base.fast_forward?(commit)
     end

lib/eternity/session.rb

@@ -91,7 +91,6 @@ def pull
         commit! author: 'System',
                 message: "Merge #{target_commit.id} into #{current_commit.id}",
                 parents: patch.commit_ids,
-                delta: nil,
                 index: write_index(patch.index_delta),
                 base: patch.base_commit.id,
                 base_delta: Blob.write(:delta, patch.base_delta)
@@ -125,9 +124,10 @@ def write_index(delta)
     end
 
     def commit!(options)
+      changes = delta
       options[:parents] ||= current_commit? ? [current_commit.id] : []
-      options[:delta]   ||= Blob.write :delta, delta
-      options[:index]   ||= write_index delta
+      options[:delta]   ||= Blob.write :delta, changes
+      options[:index]   ||= write_index changes
 
       tracker.clear
 

lib/restruct/nested_hash.rb

@@ -30,9 +30,15 @@ def key?(field)
         end
 
         def empty?
-          keys.empty?
+          size == 0
         end
 
+        def size
+          redis.call('KEYS', key['*']).count
+        end
+        alias_method :count, :size
+        alias_method :length, :size
+
         def each
           keys.each { |field| yield field, self[field] }
         end

spec/pull_spec.rb

@@ -16,6 +16,16 @@
     error.message.must_equal 'Branch not found: master'
   end
 
+  it 'Without previous commit' do
+    commit_id = '123456789'
+    Branch[:master] = commit_id
+
+    session.pull
+
+    session.current_commit.id.must_equal commit_id
+    session.branches[session.current_branch].must_equal commit_id
+  end
+
   it 'Fast-forward' do
     session[:countries].insert 'AR', name: 'Argentina'
     commit_1 = session.commit author: 'User', message: 'Commit 1'