1 files changed, 18 insertions, 4 deletions
diff --git a/app/workers/process_commit_worker.rb b/app/workers/process_commit_worker.rb
index 2f7967cf531..c0c03848a40 100644
--- a/app/workers/process_commit_worker.rb
+++ b/app/workers/process_commit_worker.rb
@@ -17,12 +17,14 @@ class ProcessCommitWorker
     project = Project.find_by(id: project_id)
 
     return unless project
+    return if commit_exists_in_upstream?(project, commit_hash)
 
     user = User.find_by(id: user_id)
 
     return unless user
 
     commit = build_commit(project, commit_hash)
+
     author = commit.author || user
 
     process_commit_message(project, commit, user, author, default)
@@ -45,8 +47,8 @@ class ProcessCommitWorker
     # therefor we use IssueCollection here and skip the authorization check in
     # Issues::CloseService#execute.
     IssueCollection.new(issues).updatable_by_user(user).each do |issue|
-      Issues::CloseService.new(project, author).
-        close_issue(issue, commit: commit)
+      Issues::CloseService.new(project, author)
+        .close_issue(issue, commit: commit)
     end
   end
 
@@ -55,8 +57,8 @@ class ProcessCommitWorker
 
     return if mentioned_issues.empty?
 
-    Issue::Metrics.where(issue_id: mentioned_issues.map(&:id), first_mentioned_in_commit_at: nil).
-      update_all(first_mentioned_in_commit_at: commit.committed_date)
+    Issue::Metrics.where(issue_id: mentioned_issues.map(&:id), first_mentioned_in_commit_at: nil)
+      .update_all(first_mentioned_in_commit_at: commit.committed_date)
   end
 
   def build_commit(project, hash)
@@ -73,4 +75,16 @@ class ProcessCommitWorker
 
     Commit.from_hash(hash, project)
   end
+
+  private
+
+  # Avoid reprocessing commits that already exist in the upstream
+  # when project is forked. This will also prevent duplicated system notes.
+  def commit_exists_in_upstream?(project, commit_hash)
+    return false unless project.forked?
+
+    upstream_project = project.forked_from_project
+    commit_id = commit_hash.with_indifferent_access[:id]
+    upstream_project.commit(commit_id).present?
+  end
 end