From baf6c1d5e2563544d9fddfde879486816cc6381b Mon Sep 17 00:00:00 2001 From: Sebastiaan van Stijn Date: Fri, 29 Jan 2021 12:17:35 +0100 Subject: [PATCH] cio: openFifos() use named return variables to use in defer() This change is mostly defensive; when checking for the returned error, it's easy to make a mistake, and check for a "local" error, not the actual returned error. This patch changes the function to use a named return variable, which is checked in the defer. Signed-off-by: Sebastiaan van Stijn --- cio/io_unix.go | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/cio/io_unix.go b/cio/io_unix.go index a92d92978..8b600673f 100644 --- a/cio/io_unix.go +++ b/cio/io_unix.go @@ -103,38 +103,36 @@ func copyIO(fifos *FIFOSet, ioset *Streams) (*cio, error) { }, nil } -func openFifos(ctx context.Context, fifos *FIFOSet) (pipes, error) { - var err error +func openFifos(ctx context.Context, fifos *FIFOSet) (f pipes, retErr error) { defer func() { - if err != nil { + if retErr != nil { fifos.Close() } }() - var f pipes if fifos.Stdin != "" { - if f.Stdin, err = fifo.OpenFifo(ctx, fifos.Stdin, syscall.O_WRONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil { - return f, errors.Wrapf(err, "failed to open stdin fifo") + if f.Stdin, retErr = fifo.OpenFifo(ctx, fifos.Stdin, syscall.O_WRONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); retErr != nil { + return f, errors.Wrapf(retErr, "failed to open stdin fifo") } defer func() { - if err != nil && f.Stdin != nil { + if retErr != nil && f.Stdin != nil { f.Stdin.Close() } }() } if fifos.Stdout != "" { - if f.Stdout, err = fifo.OpenFifo(ctx, fifos.Stdout, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil { - return f, errors.Wrapf(err, "failed to open stdout fifo") + if f.Stdout, retErr = fifo.OpenFifo(ctx, fifos.Stdout, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); retErr != nil { + return f, errors.Wrapf(retErr, "failed to open stdout fifo") } defer func() { - if err != nil && f.Stdout != nil { + if retErr != nil && f.Stdout != nil { f.Stdout.Close() } }() } if !fifos.Terminal && fifos.Stderr != "" { - if f.Stderr, err = fifo.OpenFifo(ctx, fifos.Stderr, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil { - return f, errors.Wrapf(err, "failed to open stderr fifo") + if f.Stderr, retErr = fifo.OpenFifo(ctx, fifos.Stderr, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); retErr != nil { + return f, errors.Wrapf(retErr, "failed to open stderr fifo") } } return f, nil