Bug#809623: RFS: telegram-purple/1.2.3-1

[Jakub Wilk <jwilk@debian.org>]

Hi, I happen to be i18nspector upstream.

* BenWiederhake.GitHub <BenWiederhake.GitHub@gmx.de>, 2016-01-02, 20:31:
> - i18nspector and Transifex (the service we use for our translation) 
> heavily disagree about how a po-file should look like,

Care to elaborate on how they "heavily disagree"?

> and how Russion plurals work(?!).

The Russian PO file reads:

Plural-Forms: nplurals=4; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<12 || n%100>14) ? 1 : n%10==0 || (n%10>=5 && n%10<=9) || (n%100>=11 && n%100<=14)? 2 : 3);

Even though I don't speak Russian, I can tell that this Plural-Forms 
can't possibly be correct. Here 4 plural forms are declared, but the 
expression never evaluates to 3.

I'm too lazy to make a mathematical proof that this the case, so instead 
I wrote a small program that demonstrates it. Please see the attachment. 
Let me know if the program ever stops. :-P

Now, it would be cool if i18nspector explained better what is wrong 
here. That is, instead of

E: ru_RU.po: incorrect-plural-forms 'nplurals=4; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<12 || n%100>14) ? 1 : n%10==0 || (n%10>=5 && n%10<=9) || (n%100>=11 && n%100<=14)? 2 : 3);' => 'nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2;' or 'nplurals=4; plural=n==1 ? 3 : n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2;'

which is likely to make your eyes bleed, said something like this:

E: ru_RU.po: codomain-error-in-plural-forms f(x) != 3

I hope to implement this in the future.

> - include-what-you-use Is completely useless: It doesn't recognize <stddef.h>,

This is bug #722132, which is super-annoying (and I would consider it RC 
if I were the maintainer), but IME you can often just ignore iwyu's 
moaning about missing standard headers.

> - The following check complains loudly about plurals:
> "find -type f \( -iname '*.po' -o -iname '*.pot' \) -exec msgfmt 
> --check --check-compatibility --check-accelerators 
> --output-file=/dev/null {} \;"

Using --check-compatibility is probably a bad idea. It will complain 
about things that almost everyone wants, like the header entry or plural 
forms.

--
Jakub Wilk

#include <stdio.h>

unsigned long f(unsigned long n)
{
	return n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<12 || n%100>14) ? 1 : n%10==0 || (n%10>=5 && n%10<=9) || (n%100>=11 && n%100<=14)? 2 : 3;
}

int main(int argc, char **argv)
{
	unsigned long i;
	for (i = 0; ; i++) {
		printf("f(%lu) = %lu\n", i, f(i));
		if (f(i) == 3)
			break;
	}
}