Re: [PATCH] Cygwin: spawn: Treat empty path as the current directory.

[Ken Brown <kbrown@cornell.edu>]

On 7/1/2022 7:31 PM, Takashi Yano wrote:
> On Thu, 30 Jun 2022 21:16:35 -0400
> Ken Brown wrote:
>> On 6/30/2022 11:45 AM, Ken Brown wrote:
>>> On 6/27/2022 8:44 AM, Takashi Yano wrote:
>>>> - With this patch, the empty path (empty element in PATH or PATH is
>>>>     absent) is treated as the current directory as Linux does.
>>>> Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251730.html
>>>
>>> It might be a good idea to include a comment in the code and the commit message
>>> that this feature is being added for Linux compatibility but that it is
>>> deprecated.  According to https://man7.org/linux/man-pages/man7/environ.7.html,
>>>
>>>                 As a legacy feature, a zero-length prefix (specified as
>>>                 two adjacent colons, or an initial or terminating colon)
>>>                 is interpreted to mean the current working directory.
>>>                 However, use of this feature is deprecated, and POSIX
>>>                 notes that a conforming application shall use an explicit
>>>                 pathname (e.g., .)  to specify the current working
>>>                 directory.
>>>
>>> Alternatively, maybe this is a case where we should prefer POSIX compliance to
>>> Linux compatibility.  Corinna, WDYT?
>>
>> I withdraw my suggestion.  There's already a comment in the code saying, "An
>> empty path or '.' means the current directory", so it's clear that the intention
>> was to support that feature, and the code was simply buggy.
>>
>> I've now read through the patch, and it looks good to me.  This was pretty
>> tricky to get right.
> 
> We still need to discuss whether it is better to align Linux
> behavior or just keeping POSIX compliance, don't we?

I interpreted the existing comment as meaning that a decision was already made 
at some point to align with Linux.  But it can't hurt to wait for Corinna to 
weigh in.

Ken