From: Eric Wong <e@80x24.org>
Date: Mon, 6 May 2019 23:42:31 +0000 (+0000)
Subject: spawn (Inline::C): fix off-by-one error
X-Git-Tag: v1.2.0~299
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=3bd8bec866f5540b6dce33ffcaaf4714249dcb22;hp=3bd8bec866f5540b6dce33ffcaaf4714249dcb22;p=public-inbox.git

spawn (Inline::C): fix off-by-one error

Noticed while testing on FreeBSD 11.2 amd64 with the optional
Inline::C extension using clang 6.0.0.  The end result on
FreeBSD was spawning processes failed badly and things were
immediately unusable with this enabled.

av_len is a misleading API, and I failed to read the API
comments in perl:/av.c which state:

> Note that, unlike what the name implies, it returns
> the highest index in the array, so to get the size of
> the array you need to use "av_len(av) + 1".
> This is unlike "sv_len", which returns what you would expect.

If this bug affected anybody, it would've only affected users
using both the optional Inline::C module AND set the
PERL_INLINE_DIRECTORY environment variable.

That said, I've never seen any evidence of it on Debian
GNU/Linux + gcc on any x86 variant.  That includes full 64-bit
systems, a full 32-bit system, a 64-bit system with 32-bit
userspace, across multiple gcc versions since 2016.
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