Fix cherry-picking or reverting through an MR

1 files changed, 22 insertions, 30 deletions

diff --git a/app/services/commits/change_service.rb b/app/services/commits/change_service.rb
index 8a9bcd2d053..3051ebf5e52 100644
--- a/app/services/commits/change_service.rb
+++ b/app/services/commits/change_service.rb
@@ -8,9 +8,9 @@ module Commits
       @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
@@ -26,33 +26,24 @@ module Commits
     def commit_change(action)
       raise NotImplementedError unless repository.respond_to?(action)
 
-      if @create_merge_request
-        into = @commit.public_send("#{action}_branch_name")
-        tree_branch = @start_branch
-      else
-        into = tree_branch = @target_branch
-      end
-
-      tree_id = repository.public_send(
-        "check_#{action}_content", @commit, tree_branch)
-
-      if tree_id
-        validate_target_branch(into) if @create_merge_request
+      validate_target_branch if different_branch?
 
-        repository.public_send(
-          action,
-          current_user,
-          @commit,
-          into,
-          tree_id,
-          start_project: @start_project,
-          start_branch_name: @start_branch)
+      repository.public_send(
+        action,
+        current_user,
+        @commit,
+        @target_branch,
+        start_project: @start_project,
+        start_branch_name: @start_branch)
 
-        success
-      else
+      success
+    rescue Repository::CommitError => e
+      if e.message =~ /Failed to/
         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
+      else
+        raise
       end
     end
 
@@ -66,16 +57,17 @@ module Commits
       true
     end
 
-    def validate_target_branch(new_branch)
-      # Temporary branch exists and contains the change commit
-      return if repository.find_branch(new_branch)
-
-      result = ValidateNewBranchService.new(@project, current_user)
-        .execute(new_branch)
+    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