atomic write race condition

rails · Jan 17, 2022 · 44a2971 · 44a2971
1 parent 83a4fa4
commit 44a2971
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diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
@@ -1,3 +1,5 @@
+*   Improve `File.atomic_write` error handling
+
 *   Fix `Class#descendants` and `DescendantsTracker#descendants` compatibility with Ruby 3.1.
 
     [The native `Class#descendants` was reverted prior to Ruby 3.1 release](https://bugs.ruby-lang.org/issues/14394#note-33),

diff --git a/activesupport/lib/active_support/core_ext/file/atomic.rb b/activesupport/lib/active_support/core_ext/file/atomic.rb
@@ -64,6 +64,8 @@ def self.probe_stat_in(dir) # :nodoc:
     file_name = join(dir, basename)
     FileUtils.touch(file_name)
     stat(file_name)
+  rescue Errno::ENOENT
+    file_name = nil
   ensure
     FileUtils.rm_f(file_name) if file_name
   end

diff --git a/activesupport/test/core_ext/file_test.rb b/activesupport/test/core_ext/file_test.rb
@@ -83,6 +83,10 @@ def test_atomic_write_returns_result_from_yielded_block
     File.unlink(file_name) rescue nil
   end
 
+  def test_probe_stat_in_when_no_dir
+    assert_nil File.probe_stat_in("/dir/does/not/exist")
+  end
+
   private
     def file_name
       "atomic-#{Process.pid}.file"