Commit Graph

6 Commits

Author SHA1 Message Date
Johannes Schindelin
d6c6b10817 t3[0-3]*: adjust the references to the default branch name "main"
Carefully excluding t3040, which sees independent development elsewhere
at the time of writing, we transition above-mentioned tests to the
default branch name `main`. This trick was performed via

	$ (cd t &&
	   sed -i -e 's/master/main/g' -e 's/MASTER/MAIN/g' \
		-e 's/Master/Main/g' -- t3[0-3]*.sh t3206/* &&
	   git checkout HEAD -- t3040\*)

This allows us to define `GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main`
for those tests.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 15:44:18 -08:00
Johannes Schindelin
334afbc76f tests: mark tests relying on the current default for init.defaultBranch
In addition to the manual adjustment to let the `linux-gcc` CI job run
the test suite with `master` and then with `main`, this patch makes sure
that GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME is set in all test scripts
that currently rely on the initial branch name being `master by default.

To determine which test scripts to mark up, the first step was to
force-set the default branch name to `master` in

- all test scripts that contain the keyword `master`,

- t4211, which expects `t/t4211/history.export` with a hard-coded ref to
  initialize the default branch,

- t5560 because it sources `t/t556x_common` which uses `master`,

- t8002 and t8012 because both source `t/annotate-tests.sh` which also
  uses `master`)

This trick was performed by this command:

	$ sed -i '/^ *\. \.\/\(test-lib\|lib-\(bash\|cvs\|git-svn\)\|gitweb-lib\)\.sh$/i\
	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
	' $(git grep -l master t/t[0-9]*.sh) \
	t/t4211*.sh t/t5560*.sh t/t8002*.sh t/t8012*.sh

After that, careful, manual inspection revealed that some of the test
scripts containing the needle `master` do not actually rely on a
specific default branch name: either they mention `master` only in a
comment, or they initialize that branch specificially, or they do not
actually refer to the current default branch. Therefore, the
aforementioned modification was undone in those test scripts thusly:

	$ git checkout HEAD -- \
		t/t0027-auto-crlf.sh t/t0060-path-utils.sh \
		t/t1011-read-tree-sparse-checkout.sh \
		t/t1305-config-include.sh t/t1309-early-config.sh \
		t/t1402-check-ref-format.sh t/t1450-fsck.sh \
		t/t2024-checkout-dwim.sh \
		t/t2106-update-index-assume-unchanged.sh \
		t/t3040-subprojects-basic.sh t/t3301-notes.sh \
		t/t3308-notes-merge.sh t/t3423-rebase-reword.sh \
		t/t3436-rebase-more-options.sh \
		t/t4015-diff-whitespace.sh t/t4257-am-interactive.sh \
		t/t5323-pack-redundant.sh t/t5401-update-hooks.sh \
		t/t5511-refspec.sh t/t5526-fetch-submodules.sh \
		t/t5529-push-errors.sh t/t5530-upload-pack-error.sh \
		t/t5548-push-porcelain.sh \
		t/t5552-skipping-fetch-negotiator.sh \
		t/t5572-pull-submodule.sh t/t5608-clone-2gb.sh \
		t/t5614-clone-submodules-shallow.sh \
		t/t7508-status.sh t/t7606-merge-custom.sh \
		t/t9302-fast-import-unpack-limit.sh

We excluded one set of test scripts in these commands, though: the range
of `git p4` tests. The reason? `git p4` stores the (foreign) remote
branch in the branch called `p4/master`, which is obviously not the
default branch. Manual analysis revealed that only five of these tests
actually require a specific default branch name to pass; They were
modified thusly:

	$ sed -i '/^ *\. \.\/lib-git-p4\.sh$/i\
	GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master\
	export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME\
	' t/t980[0167]*.sh t/t9811*.sh

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-19 15:44:17 -08:00
Michael Haggerty
694b7a1999 repack_without_ref(): write peeled refs in the rewritten file
When a reference that existed in the packed-refs file is deleted, the
packed-refs file must be rewritten.  Previously, the file was
rewritten without any peeled refs, even if the file contained peeled
refs when it was read.  This was not a bug, because the packed-refs
file header didn't claim that the file contained peeled values.  But
it had a performance cost, because the repository would lose the
benefit of having precomputed peeled references until pack-refs was
run again.

Teach repack_without_ref() to write peeled refs to the packed-refs
file (regardless of whether they were present in the old version of
the file).

This means that if the old version of the packed-refs file was not
fully peeled, then repack_without_ref() will have to peel references.
To avoid the expense of reading lots of loose references, we take two
shortcuts relative to pack-refs:

* If the peeled value of a reference is already known (i.e., because
  it was read from the old version of the packed-refs file), then
  output that peeled value again without any checks.  This is the
  usual code path and should avoid any noticeable overhead.  (This is
  different than pack-refs, which always re-peels references.)

* We don't verify that the packed ref is still current.  It could be
  that a packed references is overridden by a loose reference, in
  which case the packed ref is no longer needed and might even refer
  to an object that has been garbage collected.  But we don't check;
  instead, we just try to peel all references.  If peeling is
  successful, the peeled value is written out (even though it might
  not be needed any more); if not, then the reference is silently
  omitted from the output.

The extra overhead of peeling references in repack_without_ref()
should only be incurred the first time the packed-refs file is written
by a version of Git that knows about the "fully-peeled" attribute.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:10 -07:00
Michael Haggerty
c995de61cd t3211: demonstrate loss of peeled refs if a packed ref is deleted
Add a test that demonstrates that the peeled values recorded in
packed-refs are lost if a packed ref is deleted.  (The code in
repack_without_ref() doesn't even attempt to write peeled refs.)  This
will be fixed in a moment.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-01 15:33:10 -07:00
Michael Haggerty
c29c46fa2e pack-refs: add fully-peeled trait
Older versions of pack-refs did not write peel lines for
refs outside of refs/tags. This meant that on reading the
pack-refs file, we might set the REF_KNOWS_PEELED flag for
such a ref, even though we do not know anything about its
peeled value.

The previous commit updated the writer to always peel, no
matter what the ref is. That means that packed-refs files
written by newer versions of git are fine to be read by both
old and new versions of git. However, we still have the
problem of reading packed-refs files written by older
versions of git, or by other implementations which have not
yet learned the same trick.

The simplest fix would be to always unset the
REF_KNOWS_PEELED flag for refs outside of refs/tags that do
not have a peel line (if it has a peel line, we know it is
valid, but we cannot assume a missing peel line means
anything). But that loses an important optimization, as
upload-pack should not need to load the object pointed to by
refs/heads/foo to determine that it is not a tag.

Instead, we add a "fully-peeled" trait to the packed-refs
file. If it is set, we know that we can trust a missing peel
line to mean that a ref cannot be peeled. Otherwise, we fall
back to assuming nothing.

[commit message and tests by Jeff King <peff@peff.net>]

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-18 08:06:28 -07:00
Jeff King
03a8eddfd1 pack-refs: write peeled entry for non-tags
When we pack an annotated tag ref, we write not only the
sha1 of the tag object along with the ref, but also the sha1
obtained by peeling the tag. This lets readers of the
pack-refs file know the peeled value without having to
actually load the object, speeding up upload-pack's ref
advertisement.

The writer marks a packed-refs file with peeled refs using
the "peeled" trait at the top of the file. When the reader
sees this trait, it knows that each ref is either followed
by its peeled value, or it is not an annotated tag.

However, there is a mismatch between the assumptions of the
reader and writer. The writer will only peel refs under
refs/tags, but the reader does not know this; it will assume
a ref without a peeled value must not be a tag object. Thus
an annotated tag object placed outside of the refs/tags
hierarchy will not have its peeled value printed by
upload-pack.

The simplest way to fix this is to start writing peel values
for all refs. This matches what the reader expects for both
new and old versions of git.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-17 12:52:20 -07:00