Re: [PATCH 2/2] t/check-non-portable-shell: detect "FOO= shell_func", too

> Just like assigning a nonempty value, assigning an empty value to a
> shell variable when calling a function produces non-portable behavior:
> in some shells, the assignment lasts for the duration of the function
> invocation, and in others, it persists after the function returns.
> ...
> diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
> index 38bfeebd88..fd3303552b 100755
> --- a/t/check-non-portable-shell.pl
> +++ b/t/check-non-portable-shell.pl
> @@ -46,7 +46,7 @@ sub err {
>  	/(?:\$\(seq|^\s*seq\b)/ and err 'seq is not portable (use test_seq)';
>  	/\bgrep\b.*--file\b/ and err 'grep --file FILE is not portable (use grep -f FILE)';
>  	/\bexport\s+[A-Za-z0-9_]*=/ and err '"export FOO=bar" is not portable (use FOO=bar && export FOO)';
> -	/^\s*([A-Z0-9_]+=(\w+|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and
> +	/^\s*([A-Z0-9_]+=(\w*|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and