Re: `message' not outputting the newline "atomically"

[Daniele Nicolodi]

On 24-06-2019 13:48, Lars Ingebrigtsen wrote:
> So...  does this look OK?
> 
> diff --git a/src/xdisp.c b/src/xdisp.c
> index 5d70440f1c..0b45ca9e02 100644
> --- a/src/xdisp.c
> +++ b/src/xdisp.c
> @@ -10705,10 +10705,22 @@ message_to_stderr (Lisp_Object m)
>        else
>       s = m;
>  
> -      fwrite (SDATA (s), SBYTES (s), 1, stderr);
> +      /* We want to write this out with a single fwrite call so that
> +      output doesn't interleave with other processes writing to
> +      stderr at the same time. */
> +      {
> +     int length = SBYTES (s);
> +     char *string = xmalloc (length + 1);
> +     
> +     memcpy (string, SSDATA (s), length);
> +     *(string + length) = '\n';

Isn't this more naturally spelled as below?

string[length] = '\n';

> +     fwrite (string, length + 1, 1, stderr);
> +     xfree (string);
> +      }
>      }
> -  if (!cursor_in_echo_area)
> +  else if (!cursor_in_echo_area)
>      fputc ('\n', stderr);
> +
>    fflush (stderr);

I think the fflush() here can be dropped, stderr is not buffered.

>  }

Cheers,
Dan