t/perf: use $MODERN_GIT for all repo-copying steps

Since 1a0962dee (t/perf: fix regression in testing older
versions of git, 2016-06-22), we point "$MODERN_GIT" to a
copy of git that matches the t/perf script itself, and which
can be used for tasks outside of the actual timings. This is
needed because the setup done by perf scripts keeps moving
forward in time, and may use features that the older
versions of git we are testing do not have.

That commit used $MODERN_GIT to fix a case where we relied
on the relatively recent --git-path option. But if you go
back further still, there are more problems.

Since 7501b5921 (perf: make the tests work in worktrees,
2016-05-13), we use "git -C", but versions of git older than
44e1e4d67 (git: run in a directory given with -C option,
2013-09-09) don't know about "-C". So testing an old version
of git with a new version of t/perf will fail the setup
step.

We can fix this by using $MODERN_GIT during the setup;
there's no need to use the antique version, since it doesn't
affect the timings. Likewise, we'll adjust the "init"
invocation; antique versions of git called this "init-db".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/perf/perf-lib.sh b/t/perf/perf-lib.sh
index 46f08ee0870ffd2b1e0eb7d159b159d25ef61ffb..ab4b8b06ae50c5e4ee7e128ded55dea7dddf7865 100644 (file)
--- a/t/perf/perf-lib.sh
+++ b/t/perf/perf-lib.sh
@@ -83,7 +83,7 @@ test_perf_create_repo_from () {
        error "bug in the test script: not 2 parameters to test-create-repo"
        repo="$1"
        source="$2"
-       source_git="$(git -C "$source" rev-parse --git-dir)"
+       source_git="$("$MODERN_GIT" -C "$source" rev-parse --git-dir)"
        objects_dir="$("$MODERN_GIT" -C "$source" rev-parse --git-path objects)"
        mkdir -p "$repo/.git"
        (
@@ -102,7 +102,7 @@ test_perf_create_repo_from () {
        ) &&
        (
                cd "$repo" &&
-               git init -q && {
+               "$MODERN_GIT" init -q && {
                        test_have_prereq SYMLINKS ||
                        git config core.symlinks false
                } &&