Re: [PATCH v11 08/10] convert: advise canonical UTF encoding names
- Date: Fri, 09 Mar 2018 11:11:11 -0800
- From: Junio C Hamano <gitster@xxxxxxxxx>
- Subject: Re: [PATCH v11 08/10] convert: advise canonical UTF encoding names
> From: Lars Schneider <larsxschneider@xxxxxxxxx>
> The canonical name of an UTF encoding has the format UTF, dash, number,
> and an optionally byte order in upper case (e.g. UTF-8 or UTF-16BE).
> Some iconv versions support alternative names without a dash or with
> lower case characters.
> To avoid problems between different iconv version always suggest the
> canonical UTF names in advise messages.
> Signed-off-by: Lars Schneider <larsxschneider@xxxxxxxxx>
I think it is probably better to squash this to earlier step,
i.e. jumping straight to the endgame solution.
> diff --git a/convert.c b/convert.c
> index b80d666a6b..9a3ae7cce1 100644
> --- a/convert.c
> +++ b/convert.c
> @@ -279,12 +279,20 @@ static int validate_encoding(const char *path, const char *enc,
> "BOM is prohibited in '%s' if encoded as %s");
> * This advice is shown for UTF-??BE and UTF-??LE encodings.
> + * We cut off the last two characters of the encoding name
> + # to generate the encoding name suitable for BOMs.
I somehow thought that I saw "s/#/*/" in somebody's response during
the previous round?
> const char *advise_msg = _(
> "The file '%s' contains a byte order "
> - "mark (BOM). Please use %.6s as "
> + "mark (BOM). Please use UTF-%s as "
> - advise(advise_msg, path, enc);
> + const char *stripped = "";
> + char *upper = xstrdup_toupper(enc);
> + upper[strlen(upper)-2] = '\0';
> + if (!skip_prefix(upper, "UTF-", &stripped))
> + skip_prefix(stripped, "UTF", &stripped);
> + advise(advise_msg, path, stripped);
> + free(upper);
If this codepath is ever entered with "enc" that does not begin with
"UTF" (e.g. "Shift_JIS", which is impossible in the current code,
but I'll talk about future-proofing here), then neither of these
skip_prefix will trigger, and then you'd end up suggesting to use
"UTF-" that is nonsense. Perhaps initialize stripped to NULL and
force advise to segv to catch such a programmer error?