Re: [PATCH] use strbuf_addstr() for adding constant strings to a strbuf, part 2

[Junio C Hamano <gitster@pobox.com>]

René Scharfe <l.s.r@web.de> writes:

> Am 15.09.2016 um 22:01 schrieb Junio C Hamano:
>> René Scharfe <l.s.r@web.de> writes:
>> 
>>> Take this for example:
>>>
>>> -			strbuf_addf(&o->obuf, _("(bad commit)\n"));
>>> +			strbuf_addstr(&o->obuf, _("(bad commit)\n"));
>>>
>>> If there's a language that uses percent signs instead of parens or as
>>> regular letters, then they need to be escaped in the translated string
>>> before, but not after the patch.  As I wrote: silly.
>> 
>> Ahh, OK, so "This use of addf only has format part and nothing else,
>> hence the format part can be taken as-is" which is the Coccinelle rule
>> used to produce this patch is incomplete and always needs manual
>> inspection, in case the format part wanted to give a literal % in
>> the output.  E.g. it is a bug to convert this
>> 
>> 	strbuf_addf(&buf, _("this is 100%% wrong!"));
>> 
>> to
>> 
>> 	strbuf_addstr(&buf, _("this is 100%% wrong!"));
>
> Right.  Such strings seem to be quite rare in practice, though. 
>
>> Thanks for clarification.  Perhaps the strbuf.cocci rule file can
>> have some comment to warn the person who builds *.patch file to look
>> for % in E2, or something?
>
> Something like this?

Yup, with something like that I would understdood where that
puzzling question came from.

Thanks.

>
> ---
>  contrib/coccinelle/strbuf.cocci | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/contrib/coccinelle/strbuf.cocci b/contrib/coccinelle/strbuf.cocci
> index 7932d48..3f535ca 100644
> --- a/contrib/coccinelle/strbuf.cocci
> +++ b/contrib/coccinelle/strbuf.cocci
> @@ -1,3 +1,5 @@
> +// Careful, this is not fully equivalent: "%" is no longer treated
> +// specially.  Check for "%%", "%m" etc. in the format string (E2).
>  @@
>  expression E1, E2;
>  @@