1 files changed, 25 insertions, 21 deletions

diff --git a/app/services/commits/change_service.rb b/app/services/commits/change_service.rb
index 4d410f66c55..1297a792259 100644
--- a/app/services/commits/change_service.rb
+++ b/app/services/commits/change_service.rb
@@ -1,15 +1,16 @@
 module Commits
   class ChangeService < ::BaseService
-    class ValidationError < StandardError; end
-    class ChangeError < StandardError; end
+    ValidationError = Class.new(StandardError)
+    ChangeError = Class.new(StandardError)
 
     def execute
-      @source_project = params[:source_project] || @project
+      @start_project = params[:start_project] || @project
+      @start_branch = params[:start_branch]
       @target_branch = params[:target_branch]
       @commit = params[:commit]
-      @create_merge_request = params[:create_merge_request].present?
 
-      check_push_permissions unless @create_merge_request
+      check_push_permissions
+
       commit
     rescue Repository::CommitError, Gitlab::Git::Repository::InvalidBlobName, GitHooksService::PreReceiveError,
            ValidationError, ChangeError => ex
@@ -25,19 +26,21 @@ module Commits
     def commit_change(action)
       raise NotImplementedError unless repository.respond_to?(action)
 
-      into = @create_merge_request ? @commit.public_send("#{action}_branch_name") : @target_branch
-      tree_id = repository.public_send("check_#{action}_content", @commit, @target_branch)
+      validate_target_branch if different_branch?
 
-      if tree_id
-        create_target_branch(into) if @create_merge_request
+      repository.public_send(
+        action,
+        current_user,
+        @commit,
+        @target_branch,
+        start_project: @start_project,
+        start_branch_name: @start_branch)
 
-        repository.public_send(action, current_user, @commit, into, tree_id)
-        success
-      else
-        error_msg = "Sorry, we cannot #{action.to_s.dasherize} this #{@commit.change_type_title(current_user)} automatically.
+      success
+    rescue Repository::CreateTreeError
+      error_msg = "Sorry, we cannot #{action.to_s.dasherize} this #{@commit.change_type_title(current_user)} automatically.
                      A #{action.to_s.dasherize} may have already been performed with this #{@commit.change_type_title(current_user)}, or a more recent commit may have updated some of its content."
-        raise ChangeError, error_msg
-      end
+      raise ChangeError, error_msg
     end
 
     def check_push_permissions
@@ -50,16 +53,17 @@ module Commits
       true
     end
 
-    def create_target_branch(new_branch)
-      # Temporary branch exists and contains the change commit
-      return success if repository.find_branch(new_branch)
-
-      result = CreateBranchService.new(@project, current_user)
-                                  .execute(new_branch, @target_branch, source_project: @source_project)
+    def validate_target_branch
+      result = ValidateNewBranchService.new(@project, current_user)
+        .execute(@target_branch)
 
       if result[:status] == :error
         raise ChangeError, "There was an error creating the source branch: #{result[:message]}"
       end
     end
+
+    def different_branch?
+      @start_branch != @target_branch || @start_project != @project
+    end
   end
 end