Re: [PATCH 2/2] test-lib.sh: Dynamic test for the prerequisite SANITY

["Torsten Bögershausen" <tboegi@web.de>]

On 28.01.15 18:38, Junio C Hamano wrote:
> On Wed, Jan 28, 2015 at 12:28 AM, Torsten Bögershausen <tboegi@web.de> wrote:
>> On 27.01.15 23:20, Junio C Hamano wrote:
>>
>>> How about extending it like this (not tested)?
>> Thanks, this looks good: the test is more extensive,
>> I can test this next week.
>>
>>> -- >8 --
>>> From: Torsten Bögershausen <tboegi@web.de>
>>> Date: Tue, 27 Jan 2015 16:39:01 +0100
>>> Subject: [PATCH] test-lib.sh: set prerequisite SANITY by testing what we really need
>>>
>>> What we wanted out of the SANITY precondition is that the filesystem
>>> behaves sensibly with permission bits settings.
>>>
>>>  - You should not be able to remove a file in a read-only directory,
>>>
>>>  - You should not be able to tell if a file in a directory exists if
>>>    the directory lacks read or execute permission bits.
> Forgot one thing. I do not offhand know if tests that needs SANITY
> depends on this, but we may also want to check for this:
>
>  - You should not be able to write to a file that is marked as read-only.
>
> by adding something like
>
>   >sanitytest && chmod -w sanitytest && ! echo boo >sanitytest && !
> test -s sanitytest"
>
> in the mix.
>
>>> We used to cheat by approximating that condition with "is the /
>>> writable?" test and/or "are we running as root?" test.  Neither test
>>> is sufficient or appropriate in more exotic environments like
>>> Cygwin.
>> How about going this direction:
>>
>> We used to cheat by approximating that condition with "is the /
>> writable?" test and/or "are we running as root?" test. Neither test
>> is sufficient or appropriate, especially in environments like
>> Cygwin, Mingw or Mac OS X.
> OK, but MacOS X does not have SANITY problem; "is the / writable?" test
> was misdetecting and declaring a system with SANITY does not have one.
>
> Perhaps roll Cygwin and Mingw into a single Windows category? I dunno.
The whole discussion actually started with Mac OS X,
and the conclusion was that Mac OS X should have SANITY set, but hadn't,
because  / is writable (if you install from scratch):

$gmane/262389
and especially:
$gmane/262456

The whole discussion ended up a fix for t5539, and, as a different improvement,
the lazy SANITY probing - which works for me on all systems I had the chance to test it.

The code is OK (we can add more tests, as you suggested).
The only problem I can see is to put everything into a good commit-msg.