git-commit-vandalism/t/t5539-fetch-http-shallow.sh
Jeff King f4eec0ba84 t5539: make timestamp requirements more explicit
The test for "no shallow lines after receiving ACK ready" is very
sensitive to the timestamps of the commits we create. It's looking for
the fetch negotiation to send a "ready", which in turn depends on the
order in which we traverse commits during the negotiation.

It works reliably now because the base commit "7" is created without
test_commit, and thus gets a commit time matching the current system
clock. Whereas the new commits created in this test do use test_commit,
and get the usual test_tick time from 2005. So the fetch into the
"clone" repository results in a commit graph like this (I omitted some
of the "unrelated" commits for clarity; they're all just a sequence of
test_ticks):

  $ git log --graph --format='%ct %s %d'
  * 1112912953 new  (origin/master, origin/HEAD)
  * 1594322236 7  (grafted, master)
  * 1112912893 unrelated15  (origin/unrelated15, unrelated15)
  [...]
  * 1112912053 unrelated1  (origin/unrelated1, unrelated1)
  * 1112911993 new-too  (HEAD -> newnew, tag: new-too)

The important things to see are:

  - "7" is way in the future compared to the other commits

  - "new-too" in the fetching repo is older than "new" (and its
    "unrelated" ancestors) in the shallow repo

If we change our "setup shallow clone" step to use test_tick, too (and
get rid of the dependency on the system clock), then the test will fail.
The resulting graph looks like this:

  $ git log --graph --format='%ct %s %d'
  * 1112913373 new  (origin/master, origin/HEAD)
  * 1112912353 7  (grafted, master)
  * 1112913313 unrelated15  (origin/unrelated15, unrelated15)
  [...]
  * 1112912473 unrelated1  (origin/unrelated1, unrelated1)
  * 1112912413 new-too  (HEAD -> newnew, tag: new-too)

Our "new-too" is still older than "new" and "unrelated", but now "7" is
older than all of them (because it advanced test_tick, which the other
tests built on top of). In the original, we advertised "7" as the first
"have" before anything else, but now "new-too" is more recent. You'd see
the same thing in the unlikely event that the system clock was set
before our test_tick default in 2005.

Let's make the timing requirements more explicit. The important thing is
that the client advertise all of its shared commits first, before
presenting its unique "new-too" commit. We can do that and get rid of
the system clock dependency at the same time by creating all of the
shared commits around time X (using test_tick), and then creating
"new-too" with some time long before X. The resulting graph looks like
this:

  $ git log --graph --format='%ct %s %d'
  * 1500001380 new  (origin/master, origin/HEAD)
  * 1500000420 7  (grafted, master)
  * 1500001320 unrelated15  (origin/unrelated15, unrelated15)
  [...]
  * 1500000480 unrelated1  (origin/unrelated1, unrelated1)
  * 1400000060 new-too  (HEAD -> newnew, tag: new-too)

That also lets us get rid of the hacky test_tick added by f0e802ca20
(t5539: update a flaky test, 2014-07-14). That was clearly dancing
around the same problem, but only addressed the relationship between
commits created in the two subshells (which did use test_tick, but
overlapped because increments of test_tick in subshells are lost). Now
that we're using consistent and well-placed times for both lines of
history, we don't have to care about a one-tick difference between the
two sides.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-10 11:56:01 -07:00

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#!/bin/sh
test_description='fetch/clone from a shallow clone over http'
. ./test-lib.sh
. "$TEST_DIRECTORY"/lib-httpd.sh
start_httpd
commit() {
echo "$1" >tracked &&
git add tracked &&
test_tick &&
git commit -m "$1"
}
test_expect_success 'setup shallow clone' '
test_tick=1500000000 &&
commit 1 &&
commit 2 &&
commit 3 &&
commit 4 &&
commit 5 &&
commit 6 &&
commit 7 &&
git clone --no-local --depth=5 .git shallow &&
git config --global transfer.fsckObjects true
'
test_expect_success 'clone http repository' '
git clone --bare --no-local shallow "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
git clone $HTTPD_URL/smart/repo.git clone &&
(
cd clone &&
git fsck &&
git log --format=%s origin/master >actual &&
cat <<EOF >expect &&
7
6
5
4
3
EOF
test_cmp expect actual
)
'
# This test is tricky. We need large enough "have"s that fetch-pack
# will put pkt-flush in between. Then we need a "have" the server
# does not have, it'll send "ACK %s ready"
test_expect_success 'no shallow lines after receiving ACK ready' '
(
cd shallow &&
for i in $(test_seq 15)
do
git checkout --orphan unrelated$i &&
test_commit unrelated$i &&
git push -q "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" \
refs/heads/unrelated$i:refs/heads/unrelated$i &&
git push -q ../clone/.git \
refs/heads/unrelated$i:refs/heads/unrelated$i ||
exit 1
done &&
git checkout master &&
test_commit new &&
git push "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" master
) &&
(
cd clone &&
git checkout --orphan newnew &&
test_tick=1400000000 &&
test_commit new-too &&
# NEEDSWORK: If the overspecification of the expected result is reduced, we
# might be able to run this test in all protocol versions.
GIT_TRACE_PACKET="$TRASH_DIRECTORY/trace" GIT_TEST_PROTOCOL_VERSION=0 \
git fetch --depth=2 &&
grep "fetch-pack< ACK .* ready" ../trace &&
! grep "fetch-pack> done" ../trace
)
'
test_expect_success 'clone shallow since ...' '
test_create_repo shallow-since &&
(
cd shallow-since &&
GIT_COMMITTER_DATE="100000000 +0700" git commit --allow-empty -m one &&
GIT_COMMITTER_DATE="200000000 +0700" git commit --allow-empty -m two &&
GIT_COMMITTER_DATE="300000000 +0700" git commit --allow-empty -m three &&
mv .git "$HTTPD_DOCUMENT_ROOT_PATH/shallow-since.git" &&
git clone --shallow-since "300000000 +0700" $HTTPD_URL/smart/shallow-since.git ../shallow11 &&
git -C ../shallow11 log --pretty=tformat:%s HEAD >actual &&
echo three >expected &&
test_cmp expected actual
)
'
test_expect_success 'fetch shallow since ...' '
git -C shallow11 fetch --shallow-since "200000000 +0700" origin &&
git -C shallow11 log --pretty=tformat:%s origin/master >actual &&
cat >expected <<-\EOF &&
three
two
EOF
test_cmp expected actual
'
test_expect_success 'shallow clone exclude tag two' '
test_create_repo shallow-exclude &&
(
cd shallow-exclude &&
test_commit one &&
test_commit two &&
test_commit three &&
mv .git "$HTTPD_DOCUMENT_ROOT_PATH/shallow-exclude.git" &&
git clone --shallow-exclude two $HTTPD_URL/smart/shallow-exclude.git ../shallow12 &&
git -C ../shallow12 log --pretty=tformat:%s HEAD >actual &&
echo three >expected &&
test_cmp expected actual
)
'
test_expect_success 'fetch exclude tag one' '
git -C shallow12 fetch --shallow-exclude one origin &&
git -C shallow12 log --pretty=tformat:%s origin/master >actual &&
test_write_lines three two >expected &&
test_cmp expected actual
'
test_expect_success 'fetching deepen' '
test_create_repo shallow-deepen &&
(
cd shallow-deepen &&
test_commit one &&
test_commit two &&
test_commit three &&
mv .git "$HTTPD_DOCUMENT_ROOT_PATH/shallow-deepen.git" &&
git clone --depth 1 $HTTPD_URL/smart/shallow-deepen.git deepen &&
mv "$HTTPD_DOCUMENT_ROOT_PATH/shallow-deepen.git" .git &&
test_commit four &&
git -C deepen log --pretty=tformat:%s master >actual &&
echo three >expected &&
test_cmp expected actual &&
mv .git "$HTTPD_DOCUMENT_ROOT_PATH/shallow-deepen.git" &&
git -C deepen fetch --deepen=1 &&
git -C deepen log --pretty=tformat:%s origin/master >actual &&
cat >expected <<-\EOF &&
four
three
two
EOF
test_cmp expected actual
)
'
test_done