[pacman-dev] [PATCH] libmakepkg: lint all arrays for empty values

[Morgan Adamiec]

On 28/10/2020 00:46, Eli Schwartz wrote:
> On 10/27/20 8:25 PM, Morgan Adamiec wrote:
>> On 28/10/2020 00:04, Allan McRae wrote:
>>
>>> pkgnames/depends/etc where it may be an issue.  So I'm not sure this
>>> check finds anything in the "break makepkg/pacman" category.
>>
>> I disagree, it actually does break something, the srcinfio file
>>
>> Consider the following pkgbuild:
>>
>> pkgbase=foo
>> pkgname=(a b)
>> pkgver=1
>> pkgrel=1
>> arch=(any)
>>
>> license=(1)
>>
>> package_a() {
>> 	license=()
>>
>> }
>>
>> package_b() {
>> 	license=('')
>> }
>>
>> And the srcinfo file:
>>
>> pkgbase = foo
>> 	pkgver = 1
>> 	pkgrel = 1
>> 	arch = any
>> 	license = 1
>>
>> pkgname = a
>> 	license =
>>
>> pkgname = b
>> 	license =
>>
>>
>> Now package `a` overrides license to an empty array. The srcinfo
>> expresses this by putting an empty license entry.
>>
>> Now package b defines a license of `empty string`, yet it generates the
>> same output. So it's impossible to tell what the original pkgbuild
>> actually meant.
> 
> In both cases, it overrides the license=('1') into non-existence.
> 
> The question is if "There is no license" or "the license is a
> zero-length string of emptiness" is semantically meaningful. Especially
> given the author of the PKGBUILD probably intended to put the former.
> 
> Given it's a purely display-oriented field, you can absolutely stuff it
> with whatever you want, and "a zero-length string of emptiness" is not
> technically invalid even if it is stupid, whereas it's useful to catch
> makedepends=('') before makepkg -s fails to find a satisfier, root and all.
> 
>> This example may seen a little contrived, but i assure you it's not.
>> Because stuff like this is done in the wild [1] and as a maintainer of a
>> srcinfo parser it's annoying that it creates this ambiguity.
> 
> It remains unclear to me, why the ambiguity matters.
> 

I guess if you were to officially declare `Key =` means to set the key
to none then that would solve the issue of it being ambiguous

Then again that would make `license=('a' '' 'b')` parse as only as
licence=(b) seems as it was cleared before.

But funnily enough, if you build the package then pacman -Qi reports
only license a. Fun!

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <https://lists.archlinux.org/pipermail/pacman-dev/attachments/20201028/0edca8b3/attachment.sig>