rebase backends currently behave differently with empty commit messages,
largely as a side-effect of the different underlying commands on which
they are based. am-based rebases apply commits with an empty commit
message without stopping or requiring the user to specify an extra flag.
(It is interesting to note that am-based rebases are the default rebase
type, and no one has ever requested a --no-allow-empty-message flag to
change this behavior.) merge-based and interactive-based rebases (which
are ultimately based on git-commit), will currently halt on any such
commits and require the user to manually specify what to do with the
commit and continue.
One possible rationale for the difference in behavior is that the purpose
of an "am" based rebase is solely to transplant an existing history, while
an "interactive" rebase is one whose purpose is to polish a series before
making it publishable. Thus, stopping and asking for confirmation for a
possible problem is more appropriate in the latter case. However, there
are two problems with this rationale:
1) merge-based rebases are also non-interactive and there are multiple
types of rebases that use the interactive machinery but are not
explicitly interactive (e.g. when either --rebase-merges or
--keep-empty are specified without --interactive). These rebases are
also used solely to transplant an existing history, and thus also
should default to --allow-empty-message.
2) this rationale only says that the user is more accepting of stopping
in the case of an explicitly interactive rebase, not that stopping
for this particular reason actually makes sense. Exploring whether
it makes sense, requires backing up and analyzing the underlying
commands...
If git-commit did not error out on empty commits by default, accidental
creation of commits with empty messages would be a very common occurrence
(this check has caught me many times). Further, nearly all such empty
commit messages would be considered an accidental error (as evidenced by a
huge amount of documentation across version control systems and in various
blog posts explaining how important commit messages are). A simple check
for what would otherwise be a common error thus made a lot of sense, and
git-commit gained an --allow-empty-message flag for special case
overrides. This has made commits with empty messages very rare.
There are two sources for commits with empty messages for rebase (and
cherry-pick): (a) commits created in git where the user previously
specified --allow-empty-message to git-commit, and (b) commits imported
into git from other version control systems. In case (a), the user has
already explicitly specified that there is something special about this
commit that makes them not want to specify a commit message; forcing them
to re-specify with every cherry-pick or rebase seems more likely to be
infuriating than helpful. In case (b), the commit is highly unlikely to
have been authored by the person who has imported the history and is doing
the rebase or cherry-pick, and thus the user is unlikely to be the
appropriate person to write a commit message for it. Stopping and
expecting the user to modify the commit before proceeding thus seems
counter-productive.
Further, note that while empty commit messages was a common error case for
git-commit to deal with, it is a rare case for rebase (or cherry-pick).
The fact that it is rare raises the question of why it would be worth
checking and stopping on this particular condition and not others. For
example, why doesn't an interactive rebase automatically stop if the
commit message's first line is 2000 columns long, or is missing a blank
line after the first line, or has every line indented with five spaces, or
any number of other myriad problems?
Finally, note that if a user doing an interactive rebase does have the
necessary knowledge to add a message for any such commit and wants to do
so, it is rather simple for them to change the appropriate line from
'pick' to 'reword'. The fact that the subject is empty in the todo list
that the user edits should even serve as a way to notify them.
As far as I can tell, the fact that merge-based and interactive-based
rebases stop on commits with empty commit messages is solely a by-product
of having been based on git-commit. It went without notice for a long
time precisely because such cases are rare. The rareness of this
situation made it difficult to reason about, so when folks did eventually
notice this behavior, they assumed it was there for a good reason and just
added an --allow-empty-message flag. In my opinion, stopping on such
messages not desirable in any of these cases, even the (explicitly)
interactive case.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a simple directory rename testcase, in conjunction with each of the
types of rebases:
git-rebase--interactive
git-rebase--am
git-rebase--merge
and also use the same testcase for
git am --3way
This demonstrates a difference in behavior between the different rebase
backends in regards to directory rename detection.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a variety of aspects that are common to all rebases regardless
of which backend is in use; however, the behavior for these different
aspects varies in ways that could surprise users. (In fact, it's not
clear -- to me at least -- that these differences were even desirable or
intentional.) Document these differences.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase was taught the --force-rebase option in commit b2f82e05de ("Teach
rebase to rebase even if upstream is up to date", 2009-02-13). This flag
worked for the am and merge backends, but wasn't a valid option for the
interactive backend.
rebase was taught the --no-ff option for interactive rebases in commit
b499549401 ("Teach rebase the --no-ff option.", 2010-03-24), to do the
exact same thing as --force-rebase does for non-interactive rebases. This
commit explicitly documented the fact that --force-rebase was incompatible
with --interactive, though it made --no-ff a synonym for --force-rebase
for non-interactive rebases. The choice of a new option was based on the
fact that "force rebase" didn't sound like an appropriate term for the
interactive machinery.
In commit 6bb4e485cf ("rebase: align variable names", 2011-02-06), the
separate parsing of command line options in the different rebase scripts
was removed, and whether on accident or because the author noticed that
these options did the same thing, the options became synonyms and both
were accepted by all three rebase types.
In commit 2d26d533a0 ("Documentation/git-rebase.txt: -f forces a rebase
that would otherwise be a no-op", 2014-08-12), which reworded the
description of the --force-rebase option, the (no-longer correct) sentence
stating that --force-rebase was incompatible with --interactive was
finally removed.
Finally, as explained at
https://public-inbox.org/git/98279912-0f52-969d-44a6-22242039387f@xiplink.com
In the original discussion around this option [1], at one point I
proposed teaching rebase--interactive to respect --force-rebase
instead of adding a new option [2]. Ultimately --no-ff was chosen as
the better user interface design [3], because an interactive rebase
can't be "forced" to run.
We have accepted both --no-ff and --force-rebase as full synonyms for all
three rebase types for over seven years. Documenting them differently
and in ways that suggest they might not be quite synonyms simply leads to
confusion. Adjust the documentation to match reality.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git rebase has three different types: am, merge, and interactive, all of
which are implemented in terms of separate scripts. am builds on git-am,
merge builds on git-merge-recursive, and interactive builds on
git-cherry-pick. We make use of features in those lower-level commands in
the different rebase types, but those features don't exist in all of the
lower level commands so we have a range of incompatibilities. Previously,
we just accepted nearly any argument and silently ignored whichever ones
weren't implemented for the type of rebase specified. Change this so the
incompatibilities are documented, included in the testsuite, and tested
for at runtime with an appropriate error message shown.
Some exceptions I left out:
* --merge and --interactive are technically incompatible since they are
supposed to run different underlying scripts, but with a few small
changes, --interactive can do everything that --merge can. In fact,
I'll shortly be sending another patch to remove git-rebase--merge and
reimplement it on top of git-rebase--interactive.
* One could argue that --interactive and --quiet are incompatible since
--interactive doesn't implement a --quiet mode (perhaps since
cherry-pick itself does not implement one). However, the interactive
mode is more quiet than the other modes in general with progress
messages, so one could argue that it's already quiet.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git rebase is split into three types: am, merge, and interactive. Various
options imply different types, and which mode we are using determine which
sub-script (git-rebase--$type) is executed to finish the work. Not all
options work with all types, so add tests for combinations where we expect
to receive an error rather than having options be silently ignored.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
signoff is not specific to the am-backend. Also, re-order a few options
to make like things (e.g. strategy and strategy-option) be near each
other.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git rebase has many options that only work with one of its three backends.
It also has a few other pairs of incompatible options. Document these.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running t7400 in a shell you observe more output than expected:
...
ok 8 - setup - hide init subdirectory
ok 9 - setup - repository to add submodules to
ok 10 - submodule add
[master (root-commit) d79ce16] one
Author: A U Thor <author@example.com>
1 file changed, 1 insertion(+)
create mode 100644 one.t
ok 11 - redirected submodule add does not show progress
ok 12 - redirected submodule add --progress does show progress
ok 13 - submodule add to .gitignored path fails
...
Fix the output by encapsulating the setup code in test_expect_success
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When testing a reworded root commit, ensure that the squash-onto commit
which is created and amended is still the root commit.
Suggested-by: Phillip Wood <phillip.wood@talktalk.net>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"make NO_ICONV=NoThanks" did not override NEEDS_LIBICONV
(i.e. linkage of -lintl, -liconv, etc. that are platform-specific
tweaks), which has been corrected.
* es/make-no-iconv:
Makefile: make NO_ICONV really mean "no iconv"
A regression to "rebase -i --root" introduced during this cycle has
been fixed.
* js/rebase-i-root-fix:
rebase --root: fix amending root commit messages
rebase --root: demonstrate a bug while amending root commit messages
The code to read compressed bitmap was not careful to avoid reading
past the end of the file, which has been corrected.
* jk/ewah-bounds-check:
ewah: adjust callers of ewah_read_mmap()
ewah_read_mmap: bounds-check mmap reads
Update the Korean translation and change the team leader to Gwan-gyeong
Mun.
Signed-off-by: Gwan-gyeong Mun <elongbug@gmail.com>
Signed-off-by: Changwoo Ryu <cwryu@debian.org>
Reviewed-by: Gwan-gyeong Mun <elongbug@gmail.com>
Newly added codepath in merge-recursive had potential buffer
overrun, which has been fixed.
* en/rename-directory-detection:
merge-recursive: use xstrdup() instead of fixed buffer
Make zlib inflate codepath more robust against versions of zlib
that clobber unused portion of outbuf.
* jl/zlib-restore-nul-termination:
packfile: correct zlib buffer handling
"git p4" updates.
* ld/git-p4-updates:
git-p4: auto-size the block
git-p4: narrow the scope of exceptions caught when parsing an int
git-p4: raise exceptions from p4CmdList based on error from p4 server
git-p4: better error reporting when p4 fails
git-p4: add option to disable syncing of p4/master with p4
git-p4: disable-rebase: allow setting this via configuration
git-p4: add options --commit and --disable-rebase
Paths can be longer than PATH_MAX. Avoid a buffer overrun in
check_dir_renamed() by using xstrdup() to make a private copy safely.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was not "newer versions of bash" but newer versions of
bash-completion that made commit 085e2ee0e6 (completion: load
completion file for external subcommand, 2018-04-29) both necessary
and possible.
Update the corresponding RelNotes entry accordingly.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Three tests in 't7406-submodule-update' contain broken &&-chains, but
since they are all in subshells, chain-lint couldn't notice them.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code path that triggered that "BUG" really does not want to run
without an explicit commit message. In the case where we want to amend a
commit message, we have an *implicit* commit message, though: the one of
the commit to amend. Therefore, this code path should not even be
entered.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When splitting a repository, running `git rebase -i --root` to reword
the initial commit, Git dies with
BUG: sequencer.c:795: root commit without message.
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The return value of ewah_read_mmap() is now an ssize_t,
since we could (in theory) process up to 32GB of data. This
would never happen in practice, but a corrupt or malicious
.bitmap or index file could convince us to do so.
Let's make sure that we don't stuff the value into an int,
which would cause us to incorrectly move our pointer
forward. We'd always move too little, since negative values
are used for reporting errors. So the worst case is just
that we end up reporting a corrupt file, not an
out-of-bounds read.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The on-disk ewah format tells us how big the ewah data is,
and we blindly read that much from the buffer without
considering whether the mmap'd data is long enough, which
can lead to out-of-bound reads.
Let's make sure we have data available before reading it,
both for the ewah header/footer as well as for the bit data
itself. In particular:
- keep our ptr/len pair in sync as we move through the
buffer, and check it before each read
- check the size for integer overflow (this should be
impossible on 64-bit, as the size is given as a 32-bit
count of 8-byte words, but is possible on a 32-bit
system)
- return the number of bytes read as an ssize_t instead of
an int, again to prevent integer overflow
- compute the return value using a pointer difference;
this should yield the same result as the existing code,
but makes it more obvious that we got our computations
right
The included test is far from comprehensive, as it just
picks a static point at which to truncate the generated
bitmap. But in practice this will hit in the middle of an
ewah and make sure we're at least exercising this code.
Reported-by: Luat Nguyen <root@l4w.io>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Support for the --set-upstream option was removed in 52668846ea
(builtin/branch: stop supporting the "--set-upstream" option,
2017-08-17). The change did not completely remove the command
due to an issue noted in the commit's log message.
So, a test was added to ensure that a command which uses the
'--set-upstream' option fails instead of silently acting as an alias
for the '--set-upstream-to' option due to option parsing features.
To avoid confusion, clarify that the option is disabled intentionally
in the corresponding test description.
The test is expected to be around as long as we intentionally fail
on seeing the '--set-upstream' option which in turn we expect to
do for a period of time after which we can be sure that existing
users of '--set-upstream' are aware that the option is no
longer supported.
Signed-off-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
