From b36319a17cf82ee9782a572fab741938662a1c6b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rub=C3=A9n=20D=C3=A1vila?= <rdavila84@gmail.com>
Date: Fri, 5 Feb 2016 18:12:41 -0500
Subject: [PATCH] Make MRs with revert commit work.

---
 app/controllers/concerns/creates_commit.rb    | 17 ++++++++++++++---
 app/controllers/projects/commit_controller.rb |  7 +++++--
 app/models/repository.rb                      | 14 ++++++++------
 app/services/commits/revert_service.rb        | 16 ++++++++++------
 4 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/app/controllers/concerns/creates_commit.rb b/app/controllers/concerns/creates_commit.rb
index b9eb0a22f88..f8d6621999d 100644
--- a/app/controllers/concerns/creates_commit.rb
+++ b/app/controllers/concerns/creates_commit.rb
@@ -16,7 +16,7 @@ module CreatesCommit
       flash[:notice] = success_notice || "Your changes have been successfully committed."
 
       if create_merge_request?
-        success_path = new_merge_request_path
+        success_path = merge_request_exists? ? existent_merge_request_path : new_merge_request_path
         target = different_project? ? "project" : "branch"
         flash[:notice] << " You can now submit a merge request to get this change into the original #{target}."
       end
@@ -62,6 +62,17 @@ module CreatesCommit
     )
   end
 
+  def existent_merge_request_path
+    namespace_project_merge_request_path(@mr_target_project.namespace, @mr_target_project, @merge_request)
+  end
+
+  def merge_request_exists?
+    @merge_request = @mr_target_project.merge_requests.opened.where(
+                       source_branch: @mr_source_branch,
+                       target_branch: @mr_target_branch
+                     ).first
+  end
+
   def different_project?
     @mr_source_project != @mr_target_project
   end
@@ -75,7 +86,7 @@ module CreatesCommit
   end
 
   def set_commit_variables
-    @mr_source_branch = @target_branch
+    @mr_source_branch ||= @target_branch
 
     if can?(current_user, :push_code, @project)
       # Edit file in this project
@@ -89,7 +100,7 @@ module CreatesCommit
       else
         # Merge request to this project
         @mr_target_project = @project
-        @mr_target_branch = @ref
+        @mr_target_branch ||= @ref
       end
     else
       # Edit file in fork
diff --git a/app/controllers/projects/commit_controller.rb b/app/controllers/projects/commit_controller.rb
index d996b0f4ca7..21579b5629d 100644
--- a/app/controllers/projects/commit_controller.rb
+++ b/app/controllers/projects/commit_controller.rb
@@ -93,10 +93,13 @@ class Projects::CommitController < Projects::ApplicationController
   end
 
   def assign_revert_commit_vars
+    @commit = project.commit(params[:id])
     @target_branch = params[:target_branch]
-
+    @mr_source_branch = @commit.revert_branch_name
+    @mr_target_branch = @target_branch
     @commit_params = {
-      revert_commit_id: params[:id],
+      commit: @commit,
+      create_merge_request: params[:create_merge_request].present? || different_project?
     }
   end
 end
diff --git a/app/models/repository.rb b/app/models/repository.rb
index 19d898c85ea..6082148f5a2 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -622,22 +622,24 @@ class Repository
     merge_commit_sha
   end
 
-  def revert(user, commit_id, target_branch, base_branch, commit_message)
+  def revert(user, commit_id, target_branch, base_branch, commit_message, create_mr = false)
     source_sha = find_branch(base_branch).target
     target_sha = find_branch(target_branch).try(:target)
 
     # First make revert in temp branch
-    unless target_sha
-      revert_commit(user, commit_id, target_branch, base_branch, commit_message)
-    end
+    status = target_sha ? true : revert_commit(user, commit_id, target_branch, base_branch, commit_message)
 
     # Make the revert happen in the target branch
     source_sha = find_branch(target_branch).target
     target_sha = find_branch(base_branch).target
+    has_changes = is_there_something_to_merge?(source_sha, target_sha)
 
-    if is_there_something_to_merge?(source_sha, target_sha)
-      revert_commit(user, commit_id, base_branch, base_branch, commit_message)
+    if has_changes && !create_mr
+      status = revert_commit(user, commit_id, base_branch, base_branch, commit_message)
     end
+
+    ::File.open('/Users/ruben/Desktop/log.txt', 'w') { |f| f.puts "HAS CHANGES: #{has_changes && status}" }
+    has_changes && status
   end
 
   def revert_commit(user, commit_id, target_branch, base_branch, commit_message)
diff --git a/app/services/commits/revert_service.rb b/app/services/commits/revert_service.rb
index 4a364f0d86a..e1b88a9d848 100644
--- a/app/services/commits/revert_service.rb
+++ b/app/services/commits/revert_service.rb
@@ -4,8 +4,9 @@ module Commits
 
     def execute
       @source_project = params[:source_project] || @project
-      @target_branch  = params[:target_branch]
-      @commit_to_revert = @source_project.commit(params[:revert_commit_id])
+      @target_branch = params[:target_branch]
+      @commit = params[:commit]
+      @create_merge_request = params[:create_merge_request]
 
       # Check push permissions to branch
       validate
@@ -23,10 +24,13 @@ module Commits
       raw_repo = repository.rugged
 
       # Create branch with revert commit
-      reverted = repository.revert(current_user, @commit_to_revert.id,
-                                   @commit_to_revert.revert_branch_name, @target_branch,
-                                   @commit_to_revert.revert_message)
-      repository.rm_branch(current_user, @commit_to_revert.revert_branch_name)
+      reverted = repository.revert(current_user, @commit.id,
+                                   @commit.revert_branch_name, @target_branch,
+                                   @commit.revert_message, @create_merge_request)
+
+      unless @create_merge_request
+        repository.rm_branch(current_user, @commit.revert_branch_name)
+      end
 
       reverted
     end