[PATCH v3 0/2] perf: show that wildmatch() regressed for pathological cases in v2.0

Fixes the issues noted in v3, see <20170510225316.31680-1-avarab@gmail.com> (https://public-inbox.org/git/20170510225316.31680-1-avarab@gmail.com/).

In addition I was wrong about for-each-ref not being subjected to this slowdown, I was just screwing up the testcase. Fix that. Now:

    $ GIT_PERF_REPEAT_COUNT=1 GIT_PERF_MAKE_OPTS="-j6 NO_OPENSSL=Y NO_WILDMATCH=YesPlease" ./run v1.9.5 v2.12.0 p0100-globbing.sh
    Test                                                       v1.9.5            v2.12.0
    -------------------------------------------------------------------------------------------------
    0100.2: refglob((a*)^nb) against tag (a^100).t; n = 1      0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.3: refglob((a*)^nb) against tag (a^100).t; n = 2      0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.4: refglob((a*)^nb) against tag (a^100).t; n = 3      0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.5: refglob((a*)^nb) against tag (a^100).t; n = 4      0.00(0.00+0.00)   0.01(0.00+0.00) +inf
    0100.6: refglob((a*)^nb) against tag (a^100).t; n = 5      0.00(0.00+0.00)   0.16(0.15+0.00) +inf
    0100.7: refglob((a*)^nb) against tag (a^100).t; n = 6      0.00(0.00+0.00)   2.73(2.71+0.00) +inf
    0100.8: fileglob((a*)^nb) against file (a^100).t; n = 1    0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.9: fileglob((a*)^nb) against file (a^100).t; n = 2    0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.10: fileglob((a*)^nb) against file (a^100).t; n = 3   0.00(0.00+0.00)   0.00(0.00+0.00) =
    0100.11: fileglob((a*)^nb) against file (a^100).t; n = 4   0.00(0.00+0.00)   0.01(0.00+0.00) +inf
    0100.12: fileglob((a*)^nb) against file (a^100).t; n = 5   0.00(0.00+0.00)   0.16(0.15+0.00) +inf
    0100.13: fileglob((a*)^nb) against file (a^100).t; n = 6   0.00(0.00+0.00)   2.75(2.73+0.00) +inf

Ævar Arnfjörð Bjarmason (2):
  perf: add function to setup a fresh test repo
  perf: add test showing exponential growth in path globbing

 t/perf/README            |  1 +
 t/perf/p0100-globbing.sh | 43 +++++++++++++++++++++++++++++++++++++++++++
 t/perf/perf-lib.sh       | 17 +++++++++++++----
 3 files changed, 57 insertions(+), 4 deletions(-)
 create mode 100755 t/perf/p0100-globbing.sh