Re: ^M in the info files

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 10 Jan 2009 13:15:51 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: emacs-pretest-bug@gnu.org, bug-gnu-emacs@gnu.org, emacs-devel@gnu.org
> 
> The changes I installed are more thorough than what Juanma posted:
> they change both detect_coding and detect_coding_system, and also bind
> inhibit-null-byte-detection in a couple more places in info.el.

When documenting the new option, I found a strange inconsistency
between detect-coding-region/string and coding detection by
insert-file-contents.  If null bytes are detected, detect_coding sets
up to use no-conversion, but detect-coding-region/string does not call
detect_coding.  Instead, detect-coding-region/string call
detect_coding_system, which does not return no-conversion for a region
or string that include null bytes.  insert-file-contents does use
no-conversion for files that contain null bytes, but it does so
because decode_coding_gap does call detect_coding.

This creates an inconsistency for Lisp programs that do their own
decoding: if they call detect-coding-region/string for a region or
string with null bytes, they will not see no-conversion in the return
value, but insert-file-contents will use no-conversion nonetheless.

I think this inconsistency constitutes a bug.