Commit d48e5e21da ("rebase (interactive-backend): make --keep-empty the
default", 2020-02-15) turned --keep-empty (for keeping commits which
start empty) into the default. The logic underpinning that commit was:
1) 'git commit' errors out on the creation of empty commits without an
override flag
2) Once someone determines that the override is worthwhile, it's
annoying and/or harmful to required them to take extra steps in
order to keep such commits around (and to repeat such steps with
every rebase).
While the logic on which the decision was made is sound, the result was
a bit of an overcorrection. Instead of jumping to having --keep-empty
being the default, it jumped to making --keep-empty the only available
behavior. There was a simple workaround, though, which was thought to
be good enough at the time. People could still drop commits which
started empty the same way the could drop any commits: by firing up an
interactive rebase and picking out the commits they didn't want from the
list. However, there are cases where external tools might create enough
empty commits that picking all of them out is painful. As such, having
a flag to automatically remove start-empty commits may be beneficial.
Provide users a way to drop commits which start empty using a flag that
existed for years: --no-keep-empty. Interpret --keep-empty as
countermanding any previous --no-keep-empty, but otherwise leaving
--keep-empty as the default.
This might lead to some slight weirdness since commands like
git rebase --empty=drop --keep-empty
git rebase --empty=keep --no-keep-empty
look really weird despite making perfect sense (the first will drop
commits which become empty, but keep commits that started empty; the
second will keep commits which become empty, but drop commits which
started empty). However, --no-keep-empty was named years ago and we are
predominantly keeping it for backward compatibility; also we suspect it
will only be used rarely since folks already have a simple way to drop
commits they don't want with an interactive rebase.
Reported-by: Bryan Turner <bturner@atlassian.com>
Reported-by: Sami Boukortt <sami@boukortt.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Two related changes, with separate rationale for each:
Rename the 'interactive' backend to 'merge' because:
* 'interactive' as a name caused confusion; this backend has been used
for many kinds of non-interactive rebases, and will probably be used
in the future for more non-interactive rebases than interactive ones
given that we are making it the default.
* 'interactive' is not the underlying strategy; merging is.
* the directory where state is stored is not called
.git/rebase-interactive but .git/rebase-merge.
Rename the 'am' backend to 'apply' because:
* Few users are familiar with git-am as a reference point.
* Related to the above, the name 'am' makes sentences in the
documentation harder for users to read and comprehend (they may read
it as the verb from "I am"); avoiding this difficult places a large
burden on anyone writing documentation about this backend to be very
careful with quoting and sentence structure and often forces
annoying redundancy to try to avoid such problems.
* Users stumble over pronunciation ("am" as in "I am a person not a
backend" or "am" as in "the first and thirteenth letters in the
alphabet in order are "A-M"); this may drive confusion when one user
tries to explain to another what they are doing.
* While "am" is the tool driving this backend, the tool driving git-am
is git-apply, and since we are driving towards lower-level tools
for the naming of the merge backend we may as well do so here too.
* The directory where state is stored has never been called
.git/rebase-am, it was always called .git/rebase-apply.
For all the reasons listed above:
* Modify the documentation to refer to the backends with the new names
* Provide a brief note in the documentation connecting the new names
to the old names in case users run across the old names anywhere
(e.g. in old release notes or older versions of the documentation)
* Change the (new) --am command line flag to --apply
* Rename some enums, variables, and functions to reinforce the new
backend names for us as well.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have many rebase tests in the testsuite, and often the same test is
repeated multiple times just testing different backends. For those
tests that were specifically trying to test the am backend, add the --am
flag.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Different rebase backends have different treatment for commits which
start empty (i.e. have no changes relative to their parent), and the
--keep-empty option was added at some point to allow adjusting behavior.
The handling of commits which start empty is actually quite similar to
commit b00bf1c9a8 (git-rebase: make --allow-empty-message the default,
2018-06-27), which pointed out that the behavior for various backends is
often more happenstance than design. The specific change made in that
commit is actually quite relevant as well and much of the logic there
directly applies here.
It makes a lot of sense in 'git commit' to error out on the creation of
empty commits, unless an override flag is provided. However, once
someone determines that there is a rare case that merits using the
manual override to create such a commit, it is somewhere between
annoying and harmful to have to take extra steps to keep such
intentional commits around. Granted, empty commits are quite rare,
which is why handling of them doesn't get considered much and folks tend
to defer to existing (accidental) behavior and assume there was a reason
for it, leading them to just add flags (--keep-empty in this case) that
allow them to override the bad defaults. Fix the interactive backend so
that --keep-empty is the default, much like we did with
--allow-empty-message. The am backend should also be fixed to have
--keep-empty semantics for commits that start empty, but that is not
included in this patch other than a testcase documenting the failure.
Note that there was one test in t3421 which appears to have been written
expecting --keep-empty to not be the default as correct behavior. This
test was introduced in commit 00b8be5a4d ("add tests for rebasing of
empty commits", 2013-06-06), which was part of a series focusing on
rebase topology and which had an interesting original cover letter at
https://lore.kernel.org/git/1347949878-12578-1-git-send-email-martinvonz@gmail.com/
which noted
Your input especially appreciated on whether you agree with the
intent of the test cases.
and then went into a long example about how one of the many tests added
had several questions about whether it was correct. As such, I believe
most the tests in that series were about testing rebase topology with as
many different flags as possible and were not trying to state in general
how those flags should behave otherwise.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the case where we are using test_cmp_rev() to report not-equals, we
write `! test_cmp_rev`. However, since test_cmp_rev() contains
r1=$(git rev-parse --verify "$1") &&
r2=$(git rev-parse --verify "$2") &&
`! test_cmp_rev` will succeed if any of the rev-parses fail. This
behavior is not desired. We want the rev-parses to _always_ be
successful.
Rewrite test_cmp_rev() to optionally accept "!" as the first argument to
do a not-equals comparison. Rewrite `! test_cmp_rev` to `test_cmp_rev !`
in all tests to take advantage of this new functionality.
Also, rewrite the rev-parse logic to end with a `|| return 1` instead of
&&-chaining into the rev-comparison logic. This makes it obvious to
future readers that we explicitly intend on returning early if either of
the rev-parses fail.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add tests rebasing a linear branch topology to linear rebase tests
added in 2aad7cace2 ("add simple tests of consistency across rebase
types", 2013-06-06).
These tests are duplicates of two surrounding tests that do the same
with tags pointing to the same objects. Right now there's no change in
behavior being introduced, but as we'll see in a subsequent change
rebase can have different behaviors when working implicitly with
remote tracking branches.
While I'm at it add a --fork-point test, strictly speaking this is
redundant to the existing '' test, as no argument to rebase implies
--fork-point. But now it's easier to grep for tests that explicitly
stress --fork-point.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As part of an ongoing effort to make rebase have more uniform behavior,
modify the merge backend to behave like the interactive one, by
re-implementing it on top of the latter.
Interactive rebases are implemented in terms of cherry-pick rather than
the merge-recursive builtin, but cherry-pick also calls into the
recursive merge machinery by default and can accept special merge
strategies and/or special strategy options. As such, there really is
not any need for having both git-rebase--merge and
git-rebase--interactive anymore. Delete git-rebase--merge.sh and
instead implement it in builtin/rebase.c.
This results in a few deliberate but small user-visible changes:
* The progress output is modified (see t3406 and t3420 for examples)
* A few known test failures are now fixed (see t3421)
* bash-prompt during a rebase --merge is now REBASE-i instead of
REBASE-m. Reason: The prompt is a reflection of the backend in use;
this allows users to report an issue to the git mailing list with
the appropriate backend information, and allows advanced users to
know where to search for relevant control files. (see t9903)
testcase modification notes:
t3406: --interactive and --merge had slightly different progress output
while running; adjust a test to match the new expectation
t3420: these test precise output while running, but rebase--am,
rebase--merge, and rebase--interactive all were built on very
different commands (am, merge-recursive, cherry-pick), so the
tests expected different output for each type. Now we expect
--merge and --interactive to have the same output.
t3421: --interactive fixes some bugs in --merge! Wahoo!
t9903: --merge uses the interactive backend so the prompt expected is
now REBASE-i.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `--preserve-merges` mode of the `rebase` command is slated to be
deprecated soon, as the more powerful `--rebase-merges` mode is
available now, and the latter was designed with the express intent to
address the shortcomings of `--preserve-merges`' design (e.g. the
inability to reorder commits in an interactive rebase).
As such, we will eventually even remove the `--preserve-merges` support,
and along with it, its tests.
In preparation for this, and also to allow the Windows phase of our
automated tests to save some well-needed time when running the test
suite, this commit introduces a new prerequisite REBASE_P, which can be
forced to being unmet by setting the environment variable
`GIT_TEST_SKIP_REBASE_P` to any non-empty string.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In this developer's earlier attempt to accelerate interactive rebases by
converting large parts from Unix shell script into portable, performant
C, the --root handling was specifically excluded (to simplify the task a
little bit; it still took over a year to get that reduced set of patches
into Git proper).
This patch ties up that loose end: now only --preserve-merges uses the
slow Unix shell script implementation to perform the interactive rebase.
As the rebase--helper reports progress to stderr (unlike the scripted
interactive rebase, which reports it to stdout, of all places), we have
to adjust a couple of tests that did not expect that for `git rebase -i
--root`.
This patch fixes -- at long last! -- the really old bug reported in
6a6bc5bdc4 (add tests for rebasing root, 2013-06-06) that rebasing with
--root *always* rewrote the root commit, even if there were no changes.
The bug still persists in --preserve-merges mode, of course, but that
mode will be deprecated as soon as the new --rebase-merges mode
stabilizes, anyway.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If there are empty commits on the left hand side of $upstream...HEAD
then the empty commits on the right hand side that we want to keep are
being pruned.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase --merge accepts --keep-empty but just ignores it, by using an
implicit interactive rebase the user still gets the rename detection
of a merge based rebase but with with --keep-empty support.
If rebase --keep-empty without --interactive or --merge stops for the
user to resolve merge conflicts then 'git rebase --continue' will
fail. This is because it uses a different code path that does not
create $git_dir/rebase-apply. As rebase --keep-empty was implemented
using cherry-pick it has never supported the am options and now that
interactive rebases support --signoff there is no loss of
functionality by using an implicit interactive rebase.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If there are empty commits on the left hand side of $upstream...HEAD
then the empty commits on the right hand side that we want to keep are
pruned by --cherry-pick. Fix this by using --cherry-mark instead of
--cherry-pick and keeping the commits that are empty or are not marked
as cherry-picks.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Absent this fix, attempts to rebase an orphan branch using "rebase -m"
fails with:
$ git rebase -m ORPHAN_TARGET_BASE
First, rewinding head to replay your work on top of it...
fatal: Could not parse object 'ORPHAN_ROOT_SHA^'
Unknown exit code (128) from command: git-merge-recursive ORPHAN_ROOT_SHA^ -- HEAD ORPHAN_ROOT_SHA
To fix, this will only include the rebase root's parent as a base if it exists,
so that in cases of rebasing an orphan branch, it is a simple two-way merge.
Note the default rebase behavior does not fail:
$ git rebase ORPHAN_TARGET_BASE
First, rewinding head to replay your work on top of it...
Applying: ORPHAN_ROOT_COMMIT_MSG
Using index info to reconstruct a base tree...
A few tests were expecting the old behaviour to forbid rebasing such
a history with "rebase -m", which now need to expect them to succeed.
Signed-off-by: Ben Woosley <ben.woosley@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The recently introduced tests used uppercase letters to denote
cherry-picks of commits having the corresponding lowercase letter names.
The helper functions also set up tags with the names of the commits.
But this constellation fails on case-insensitive file systems because
there cannot be distinct tags with names that differ only in case.
Use a less subtle convention for the names of cherry-picked commits.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
