The breaks in the &&-chain in this test went unnoticed because the
"magic exit code 117" &&-chain checker built into test-lib.sh only
recognizes broken &&-chains at the top-level; it does not work within
`{...}` groups, `(...)` subshells, `$(...)` substitutions, or within
bodies of compound statements, such as `if`, `for`, `while`, `case`,
etc. Furthermore, `chainlint.sed` detects broken &&-chains only in
`(...)` subshells. Thus, the &&-chain breaks in this test fall into the
blind spots of the &&-chain linters.
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change introduced the 'git rebase --update-refs' option
which added 'update-ref <ref>' commands to the todo list of an
interactive rebase.
Teach Git to record the HEAD position when reaching these 'update-ref'
commands. The ref/before/after triple is stored in the
$GIT_DIR/rebase-merge/update-refs file. A previous change parsed this
file to avoid having other processes updating the refs in that file
while the rebase is in progress.
Not only do we update the file when the sequencer reaches these
'update-ref' commands, we then update the refs themselves at the end of
the rebase sequence. If the rebase is aborted before this final step,
then the refs are not updated. The 'before' value is used to ensure that
we do not accidentally obliterate a ref that was updated concurrently
(say, by an older version of Git or a third-party tool).
Now that the 'git rebase --update-refs' command is implemented to write
to the update-refs file, we can remove the fake construction of the
update-refs file from a test in t2407-worktree-heads.sh.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When working on a large feature, it can be helpful to break that feature
into multiple smaller parts that become reviewed in sequence. During
development or during review, a change to one part of the feature could
affect multiple of these parts. An interactive rebase can help adjust
the multi-part "story" of the branch.
However, if there are branches tracking the different parts of the
feature, then rebasing the entire list of commits can create commits not
reachable from those "sub branches". It can take a manual step to update
those branches.
Add a new --update-refs option to 'git rebase -i' that adds 'update-ref
<ref>' steps to the todo file whenever a commit that is being rebased is
decorated with that <ref>. At the very end, the rebase process updates
all of the listed refs to the values stored during the rebase operation.
Be sure to iterate after any squashing or fixups are placed. Update the
branch only after those squashes and fixups are complete. This allows a
--fixup commit at the tip of the feature to apply correctly to the sub
branch, even if it is fixing up the most-recent commit in that part.
This change update the documentation and builtin to accept the
--update-refs option as well as updating the todo file with the
'update-ref' commands. Tests are added to ensure that these todo
commands are added in the correct locations.
This change does _not_ include the actual behavior of tracking the
updated refs and writing the new ref values at the end of the rebase
process. That is deferred to a later change.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The branch_checked_out() helper helps commands like 'git branch' and
'git fetch' from overwriting refs that are currently checked out in
other worktrees.
A future update to 'git rebase' will introduce a new '--update-refs'
option which will update the local refs that point to commits that are
being rebased. To avoid collisions as the rebase completes, we want to
make the future data store for these refs to be considered by
branch_checked_out().
The data store is a plaintext file inside the 'rebase-merge' directory
for that worktree. The file lists refnames followed by two OIDs, each on
separate lines. The OIDs will be used to store the original values of
the refs and the to-be-written values as the rebase progresses, but can
be ignored at the moment.
Create a new sequencer_get_update_refs_state() method that parses this
file and populates a struct string_list with the ref-OID pairs. We can
then use this list to add to the current_checked_out_branches strmap
used by branch_checked_out().
To properly navigate to the rebase directory for a given worktree,
extract the static strbuf_worktree_gitdir() method to a public API
method.
We can test that this works without having Git write this file by
artificially creating one in our test script, at least until 'git rebase
--update-refs' is implemented and we can use it directly.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tests in t2407 that verify the branch_checked_out() helper in the
case of bisects and rebases were added by 9347303db89 (branch: check for
bisects and rebases, 2022-06-08). However, that commit failed to check
for rebases that are using the 'apply' backend.
Add a test that checks the apply backend. The implementation was already
correct here, but it is good to have regression tests before modifying
the implementation further.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tests added by d2ba271aad (branch: check for bisects and rebases,
2022-06-14) modified hidden state to verify the branch_checked_out()
helper. While this indeed checks that the method implementation is _as
designed_, it doesn't show that it is _correct_. Specifically, if 'git
bisect' or 'git rebase' change their back-end for preserving refs, then
these tests do not demonstrate that drift as a bug in
branch_checked_out().
Modify the tests in t2407 to actually rely on a paused bisect or rebase.
This requires adding the !SANITIZE_LEAK prereq for tests using those
builtins. The logic is still tested for leaks in the final test which
does set up that back-end directly for an error state that should not be
possible using Git commands.
Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The branch_checked_out() method populates a strmap linking a refname to
a worktree that has that branch checked out. While unlikely, it is
possible that a bug or filesystem manipulation could create a scenario
where the same ref is checked out in multiple places. Further, there are
some states in an interactive rebase where HEAD and REBASE_HEAD point to
the same ref, leading to multiple insertions into the strmap. In either
case, the strmap_put() method returns the old value which is leaked.
Update branch_checked_out() to consume that pointer and free it.
Add a test in t2407 that checks this erroneous case. The test "checks
itself" by first confirming that the filesystem manipulations it makes
trigger the branch_checked_out() logic, and then sets up similar
manipulations to make it look like there are multiple worktrees pointing
to the same ref.
While TEST_PASSES_SANITIZE_LEAK would be helpful to demonstrate the
leakage and prevent it in the future, t2407 uses helpers such as 'git
clone' that cause the test to fail under that mode.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the last current use of find_shared_symref() that can easily be
replaced by branch_checked_out(). The benefit of this switch is that the
code is a bit simpler, but also it is faster on repeated calls.
The remaining uses of find_shared_symref() are non-trivial to remove, so
we probably should not continue in that direction:
* builtin/notes.c uses find_shared_symref() with "NOTES_MERGE_REF"
instead of "HEAD", so it doesn't have an immediate analogue with
branch_checked_out(). Perhaps we should consider extending it to
include that symref in addition to HEAD, BISECT_HEAD, and
REBASE_HEAD.
* receive-pack.c checks to see if a worktree has a checkout for the ref
that is being updated. The tricky part is that it can actually decide
to update the worktree directly instead of just skipping the update.
This all depends on the receive.denyCurrentBranch config option. The
implementation currenty cares about receiving the worktree in the
result, so the current branch_checked_out() prototype is insufficient
currently. This is something to investigate later, though, since a
large number of refs could be updated at the same time and using the
strmap implementation of branch_checked_out() could be beneficial.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fetching refs from a remote, it is possible that the refspec will
cause use to overwrite a ref that is checked out in a worktree. The
existing logic in builtin/fetch.c uses a possibly-slow mechanism. Update
those sections to use the new, more efficient branch_checked_out()
helper.
These uses were not previously tested, so add a test case that can be
used for these kinds of collisions. There is only one test now, but more
tests will be added as other consumers of branch_checked_out() are
added.
Note that there are two uses in builtin/fetch.c, but only one of the
messages is tested. This is because the tested check is run before
completing the fetch, and the untested check is not reachable without
concurrent updates to the filesystem. Thus, it is beneficial to keep
that extra check for the sake of defense-in-depth. However, we should
not attempt to test the check, as the effort required is too
complicated to be worth the effort. This use in update_local_ref()
also requires a change in the error message because we no longer have
access to the worktree struct, only the path of the worktree. This error
is so rare that making a distinction between the two is not critical.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The branch_checked_out() helper was added by the previous change, but it
used an over-simplified view to check if a branch is checked out. It
only focused on the HEAD symref, but ignored whether a bisect or rebase
was happening.
Teach branch_checked_out() to check for these things, and also add tests
to ensure that we do not lose this functionality in the future.
Now that this test coverage exists, we can safely refactor
validate_new_branchname() to use branch_checked_out().
Note that we need to prepend "refs/heads/" to the 'state.branch' after
calling wt_status_check_*(). We also need to duplicate wt->path so the
value is not freed at the end of the call.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The validate_new_branchname() method contains a check to see if a branch
is checked out in any non-bare worktree. This is intended to prevent a
force push that will mess up an existing checkout. This helper is not
suitable to performing just that check, because the method will die()
when the branch is checked out instead of returning an error code.
Create a new branch_checked_out() helper that performs the most basic
form of this check. To ensure we can call branch_checked_out() in a loop
with good performance, do a single preparation step that iterates over
all worktrees and stores their current HEAD branches in a strmap. The
branch_checked_out() helper can then discover these branches using a
hash lookup.
This helper is currently missing some key functionality. Namely: it
doesn't look for active rebases or bisects which mean that the branch is
"checked out" even though HEAD doesn't point to that ref. This
functionality will be added in a coming change.
We could use branch_checked_out() in validate_new_branchname(), but this
missing functionality would be a regression. However, we have no tests
that cover this case!
Add a new test script that will be expanded with these cross-worktree
ref updates. The current tests would still pass if we refactored
validate_new_branchname() to use this version of branch_checked_out().
The next change will fix that functionality and add the proper test
coverage.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
