From a3f1db6a6890dee1369609492f20f6d994cf8e0e Mon Sep 17 00:00:00 2001
From: kumojima <kumojima@gmail.com>
Date: Tue, 16 Jun 2026 21:30:07 +0900
Subject: fix shorten filename with long extension

---
 app/models/attachment.rb     |  7 +++++--
 test/unit/attachment_test.rb | 13 +++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 6932d79a2..2adfc9f9f 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -596,12 +596,15 @@ class Attachment < ApplicationRecord
     def create_diskfile(filename, directory=nil, &)
       timestamp = DateTime.now.strftime("%y%m%d%H%M%S")
       ascii = ''
-      if %r{^[a-zA-Z0-9_.-]*$}.match?(filename) && filename.length <= 50
+      max_filename_length = 50
+      if %r{^[a-zA-Z0-9_.-]*$}.match?(filename) && filename.length <= max_filename_length
         ascii = filename
       else
         ascii = ActiveSupport::Digest.hexdigest(filename)
         # keep the extension if any
-        ascii << $1 if filename =~ %r{(\.[a-zA-Z0-9]+)$}
+        if filename =~ %r{(\.[a-zA-Z0-9]+)$} && "#{ascii}#{$1}".length <= max_filename_length
+          ascii << $1
+        end
       end
 
       path = File.join storage_path, directory.to_s
diff --git a/test/unit/attachment_test.rb b/test/unit/attachment_test.rb
index 387da73c5..2107e389f 100644
--- a/test/unit/attachment_test.rb
+++ b/test/unit/attachment_test.rb
@@ -81,6 +81,19 @@ class AttachmentTest < ActiveSupport::TestCase
     assert_equal 255, a.filename.length
   end
 
+  def test_shorted_filename_if_too_long_extension
+    file = mock_file_with_options(:original_filename => "file.#{'a'*250}")
+
+    a = Attachment.new(:container => Issue.find(1),
+                       :file => file,
+                       :author => User.find(1))
+    assert a.save
+    a.reload
+    # timestamp_hexdigest
+    assert_equal 12 + 1 + 32, a.disk_filename.length
+    assert_equal 255, a.filename.length
+  end
+
   def test_copy_should_preserve_attributes
     # prevent re-use of data from other attachments with equal contents
     Attachment.where('id <> 1').destroy_all
-- 
2.43.0