Re: Why isn't "sed -n p" identical to "cat"?

[Assaf Gordon]

On 2019-01-09 3:40 p.m., Assaf Gordon wrote:
[...]
> If this is deemed a bug, it is easily fixed with this patch:
>
> diff --git a/sed/execute.c b/sed/execute.c
> index 76bba4f..a97a9d1 100644
> --- a/sed/execute.c
> +++ b/sed/execute.c
> @@ -1653,6 +1653,7 @@ process_files (struct vector *the_program, char 
> **argv)
>
>     line_init (&line, NULL, INITIAL_BUFFER_SIZE);
>     line_init (&hold, NULL, 0);
> +  hold.chomped = false;
>     line_init (&buffer, NULL, 0);
>
>     input.reset_at_next_file = true;
>
>
> With a note: "pattern.chomped" should start as TRUE, as some
> test depends on it - so i'm not changing the default in 'line_init'.

Prompted by https://bugs.gnu.org/34133 , I noticed that the above
change does affect existing behavior:


  $ printf "%s\n" b | sed-4.7 'G;H' | od -tc
  0000000   b  \n  \n
  0000003

  $ printf "%s\n" b | ./sed/sed-with-hold-chomped 'G;H' | od -tc
  0000000   b  \n
  0000002

All other implementations output two "\n\n" (like GNU sed currently
does), so this is another reason to keep the code as-is.

regards,
 - assaf