bug#65156: 29.1; Reading from pipe with --insert or insert-file-contents no longer supported

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 11 Aug 2023 10:18:16 -0700
> Cc: mail@lucaswerkmeister.de, larsi@gnus.org, 65156@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> 
> diff --git a/src/fileio.c b/src/fileio.c
> index 52bbaa61fc2..40c870331b8 100644
> --- a/src/fileio.c
> +++ b/src/fileio.c
> @@ -4031,10 +4031,9 @@ because (1) it preserves some marker positions (in unchanged portions
>  undo list.  When REPLACE is non-nil, the second return value is the
>  number of characters that replace previous buffer contents.
>  
> -If REPLACE is the symbol `if-regular', then eschew preserving marker
> -positions or the undo list if REPLACE is nil if FILENAME is not a
> -regular file.  Otherwise, signal an error if REPLACE is non-nil and
> -FILENAME is not a regular file.
> +If REPLACE is non-nil and FILENAME is not a regular file, act as if
> +REPLACE were nil if REPLACE is the symbol `if-regular' and signal an
> +error otherwise.

This is fine, but I think instead of "act as if REPLACE were nil" we
should explicitly say that the buffer is erased and the file's
contents is inserted.