bug#20623: XML and HTML files with encoding/charset="utf-8" declaration loose BOM; Coding system is reset from utf-8-with-signature to utf-8 on save

[Vincent Lefevre <vincent@vinc17.net>]

On 2018-08-11 12:15:31 +0300, Eli Zaretskii wrote:
> In this case, I cannot but express my extreme surprise to see such a
> minor issue described as "grave".  The alleged data loss is minor, if
> it exists at all (the BOM is not data important for the user,

You're completely wrong. The presence of BOM or not is very important
for some applications, such as Firefox (not to determine the charset,
but the MIME type of local files).

> nor data whose loss cannot be easily repaired).

It can be repaired, but the problems are the user doesn't know
what's going on and this breaks things. If some package removed
the execute permission of some utility in /bin, this would also
be a grave bug, though it can easily been repaired.

> The unspecified "breakage in
> other applications" cannot be considered without the missing details,
> but in general I'd be surprised to hear about modern applications
> (browsers?) that really need a BOM in UTF-8 encoded HTML files to the
> degree that the lack of BOM causes them to "break" in some way; if
> they do, it could arguably be a bug in those applications.

Firefox. And that's actually the way I detected the bug, after
hours of trying to find why it was behaving in an inconsistent way.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)