From ce8d59de4c575f25a0f9fa777993829878f22dcc Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Thu, 29 Jan 2026 18:34:06 +0000
Subject: [PATCH] Add a danger warning for changes to vendored files

---
 Dangerfile | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Dangerfile b/Dangerfile
index 8249b561a..49b4dd445 100644
--- a/Dangerfile
+++ b/Dangerfile
@@ -25,6 +25,20 @@ else
   auto_label.set(pr_number, "inappropriate-translations", "B60205")
 end
 
+# Get list of vendored files which are modified
+modified_vendor_files = git.modified_files.select do |file|
+  file.start_with?("vendor")
+end
+
+# Report if some vendored file is modified
+if modified_vendor_files.empty?
+  auto_label.remove("vendor-changes")
+else
+  modified_files_str = modified_vendor_files.map { |file| "`#{file}`" }.join(", ")
+  warn("The following vendored files have been modified: #{modified_files_str}. Vendored files should be updated upstream.")
+  auto_label.set(pr_number, "vendor-changes", "B60205")
+end
+
 # Report if there are merge-commits in PR
 if git.commits.any? { |c| c.parents.count > 1 }
   warn("Merge commits are found in PR. Please rebase to get rid of the merge commits in this PR, see CONTRIBUTING.md.")
-- 
2.39.5