ruby/rubygems-3.5.17-Avoid-another-race-condition-of-open-mode.patch

From 2daad257bee7a500e18ebe553e79487b267fb140 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Mon, 12 Aug 2024 20:18:34 +0900
Subject: [PATCH] Avoid another race condition of open mode

Instead, just open in CREATE and APPEND mode.
Also, move the workaround for old Solaris as fallback to retry.
---
 lib/rubygems.rb | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 2b52cde0a749..c51ba69203cb 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -778,24 +778,20 @@ def self.open_file(path, flags, &block)
     File.open(path, flags, &block)
   end
 
+  MODE_TO_FLOCK = IO::RDONLY | IO::APPEND | IO::CREAT # :nodoc:
+
   ##
   # Open a file with given flags, and protect access with flock
 
   def self.open_file_with_flock(path, &block)
-    flags = File.exist?(path) ? "r+" : "a+"
-
-    File.open(path, flags) do |io|
+    File.open(path, MODE_TO_FLOCK) do |io|
       begin
         io.flock(File::LOCK_EX)
       rescue Errno::ENOSYS, Errno::ENOTSUP
+      rescue Errno::ENOLCK # NFS
+        raise unless Thread.main == Thread.current
       end
       yield io
-    rescue Errno::ENOLCK # NFS
-      if Thread.main != Thread.current
-        raise
-      else
-        open_file(path, flags, &block)
-      end
     end
   end