The GETTEXT_POISON=YesPlease compile-time testing option added in my
bb946bba ("i18n: add GETTEXT_POISON to simulate unfriendly
translator", 2011-02-22) has been slowly bitrotting as strings have
been marked for translation, and new tests have been added without
running it.

I brought this up on the list ("[BUG] test suite broken with
GETTEXT_POISON=YesPlease", [1]) asking whether this mode was useful at
all anymore. At least one person occasionally uses it, and Lars
Schneider offered to change one of the the Travis builds to run in
this mode, so fix up the failing ones.

My test setup runs most of the tests, with the notable exception of
skipping all the p4 tests, so it's possible that there's still some
lurking regressions I haven't fixed.

1. <CACBZZX62+acvi1dpkknadTL827mtCm_QesGSZ=6+UnyeMpg8+Q@mail.gmail.com>
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Every once in a while someone complains to the mailing list to have
run into this weird assertion[1]. The usual response from the mailing
list is link to old discussions[2], and acknowledging the problem
stating it is known.

This patch accomplishes two things:

  1. Switch assert() to die("BUG") to give a more readable message.

  2. Take one of the cases where we hit a BUG and turn it into a normal
     "there was something wrong with the input" message.

     This assertion triggered for cases where there wasn't a programming
     bug, but just bogus input. In particular, if the user asks for a
     pathspec that is inside a submodule, we shouldn't assert() or
     die("BUG"); we should tell the user their request is bogus.

     The only reason we did not check for it, is the expensive nature
     of such a check, so callers avoid setting the flag
     PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE. However when we die due
     to bogus input, the expense of CPU cycles spent outweighs the user
     wondering what went wrong, so run that check unconditionally before
     dying with a more generic error message.

Note: There is a case (e.g. "git -C submodule add .") in which we call
strip_submodule_slash_expensive, as git-add requests it via the flag
PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE, but the assert used to
trigger nevertheless, because the flag PATHSPEC_LITERAL was not set,
such that we executed

	if (item->nowildcard_len < prefixlen)
		item->nowildcard_len = prefixlen;

and prefixlen was not adapted (e.g. it was computed from "submodule/")
So in the die_inside_submodule_path function we also need handle paths,
that were stripped before, i.e. are the exact submodule path. This
is why the conditions in die_inside_submodule_path are slightly
different than in strip_submodule_slash_expensive.

[1] https://www.google.com/search?q=item-%3Enowildcard_len
[2] http://git.661346.n2.nabble.com/assert-failed-in-submodule-edge-case-td7628687.html
    https://www.spinics.net/lists/git/msg249473.htmlHelped-by: NJeff King <peff@peff.net>
Helped-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>