Prevent dangling cat-file calls (goroutine alternative) (#19454) If an `os/exec.Command` is passed non `*os.File` as an input/output, go will create `os.Pipe`s and wait for their closure in `cmd.Wait()`. If the code following this is responsible for closing `io.Pipe`s or other handlers then on process death from context cancellation the `Wait` can hang. There are two possible solutions: 1. use `os.Pipe` as the input/output as `cmd.Wait` does not wait for these. 2. create a goroutine waiting on the context cancellation that will close the inputs. This PR provides the second option - which is a simpler change that can be more easily backported. Closes #19448 Signed-off-by: Andrew Thornton <art27@cantab.net>

Changes

1 changed files (+12/-0)

• modules/git/batch_reader.go
  • @@ -57,6 +57,12 @@ func CatFileBatchCheck(ctx context.Context, repoPath string) (WriteCloserError,
    <-closed } + // Ensure cancel is called as soon as the provided context is cancelled + go func() { + <-ctx.Done() + cancel() + }() + _, filename, line, _ := runtime.Caller(2) filename = strings.TrimPrefix(filename, callerPrefix)
  • @@ -101,6 +107,12 @@ func CatFileBatch(ctx context.Context, repoPath string) (WriteCloserError, *bufi
    <-closed } + // Ensure cancel is called as soon as the provided context is cancelled + go func() { + <-ctx.Done() + cancel() + }() + _, filename, line, _ := runtime.Caller(2) filename = strings.TrimPrefix(filename, callerPrefix)