Re: [PATCH v1 1/2] t0027: Correct raciness in NNO test

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

On Sat, Aug 13, 2016 at 06:50:19PM +0200, Johannes Sixt wrote:
> Am 12.08.2016 um 18:51 schrieb tboegi@web.de:
> >From: Torsten Bögershausen <tboegi@web.de>
> >
> >When a non-reversible CRLF conversion is done in "git add",
> >a warning is printed on stderr (or Git dies, depending on checksafe)
> >
> >The function commit_chk_wrnNNO() in t0027 was written to test this,
> >but did the wrong thing: Instead of looking at the warning
> >from "git add", it looked at the warning from "git commit".
> >
> >This is racy because "git commit" may not have to do CRLF conversion
> >at all if it can use the sha1 value from the index (which depends on
> >whether "add" and "commit" run in a single second).
> >
> >Correct this and replace the commit for each and every file with a commit
> >of all files in one go.
> 
> The new test code does not only fix the race condition, but also
> tests different things, or prepares test cases in a different
> manner. I would have appreciated an explanation why this is
> necessary. Is it "on my machine, the race condition was triggered
> consistently for a bunch of tests, and so I recorded the wrong
> expected output in the test cases"?
> 
Good point. The origanal intention was to let t0027 pass, and fix
the bug in convert.c in a later commit.
(and rename NNO in a 3rd commit, that is postponed until we figured this out).

Looking at t0027, it turns out that the changes in the test matrix done in 1/2
are reverted in 2/2.
This is not a good thing.
Either (a) they should be marked as test_expect_failure in 1/2 and
corrected in 2/2,
or (b) 1/2 and 2/2 are squashed together and the noise in t0027 is minimal.
I'll send a patch for (b) in a second.