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>
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>
When an interactive rebase wants to recreate a root commit, it
- first creates a new, empty root commit,
- checks it out,
- converts the next `pick` command so that it amends the empty root
commit
Introduce support in the sequencer to handle such an empty root commit,
by looking for the file <GIT_DIR>/rebase-merge/squash-onto; if it exists
and contains a commit name, the sequencer will compare the HEAD to said
root commit, and if identical, a new root commit will be created.
While converting scripted code into proper, portable C, we also do away
with the old "amend with an empty commit message, then cherry-pick
without committing, then amend again" dance and replace it with code
that uses the internal API properly to do exactly what we want: create a
new root commit.
To keep the implementation simple, we always spawn `git commit` to create
new root commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch extracts the code from is_index_unchanged() to initialize or
update the index' cache tree (i.e. a tree object reflecting the current
index' top-level tree).
The new helper will be used in the upcoming code to support `git rebase
-i --root` via the sequencer.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --rebase-merges mode is probably not half as intuitive to use as
its inventor hopes, so let's document it some.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running `git rebase --rebase-merges` non-interactively with an
ancestor of HEAD as <upstream> (or leaving the todo list unmodified),
we would ideally recreate the exact same commits as before the rebase.
However, if there are commits in the commit range <upstream>.. that do not
have <upstream> as direct ancestor (i.e. if `git log <upstream>..` would
show commits that are omitted by `git log --ancestry-path <upstream>..`),
this is currently not the case: we would turn them into commits that have
<upstream> as direct ancestor.
Let's illustrate that with a diagram:
C
/ \
A - B - E - F
\ /
D
Currently, after running `git rebase -i --rebase-merges B`, the new branch
structure would be (pay particular attention to the commit `D`):
--- C' --
/ \
A - B ------ E' - F'
\ /
D'
This is not really preserving the branch topology from before! The
reason is that the commit `D` does not have `B` as ancestor, and
therefore it gets rebased onto `B`.
This is unintuitive behavior. Even worse, when recreating branch
structure, most use cases would appear to want cousins *not* to be
rebased onto the new base commit. For example, Git for Windows (the
heaviest user of the Git garden shears, which served as the blueprint
for --rebase-merges) frequently merges branches from `next` early, and
these branches certainly do *not* want to be rebased. In the example
above, the desired outcome would look like this:
--- C' --
/ \
A - B ------ E' - F'
\ /
-- D' --
Let's introduce the term "cousins" for such commits ("D" in the
example), and let's not rebase them by default. For hypothetical
use cases where cousins *do* need to be rebased, `git rebase
--rebase=merges=rebase-cousins` needs to be used.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar to the `preserve` mode simply passing the `--preserve-merges`
option to the `rebase` command, the `merges` mode simply passes the
`--rebase-merges` option.
This will allow users to conveniently rebase non-trivial commit
topologies when pulling new commits, without flattening them.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git merge` command does not allow merging commits that are already
reachable from HEAD: `git merge HEAD^`, for example, will report that we
are already up to date and not change a thing.
In an interactive rebase, such a merge could occur previously, e.g. when
competing (or slightly modified) versions of a patch series were applied
upstream, and the user had to `git rebase --skip` all of the local
commits, and the topic branch becomes "empty" as a consequence.
Let's teach the todo command `merge` to behave the same as `git merge`.
Seeing as it requires some low-level trickery to create such merges with
Git's commands in the first place, we do not even have to bother to
introduce an option to force `merge` to create such merge commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the previous patches, we implemented the basic functionality of the
`git rebase -i --rebase-merges` command, in particular the `merge`
command to create merge commits in the sequencer.
The interactive rebase is a lot more these days, though, than a simple
cherry-pick in a loop. For example, it calls the post-rewrite hook (if
any) after rebasing with a mapping of the old->new commits.
This patch implements the post-rewrite handling for the `merge` command
we just introduced. The other commands that were added recently (`label`
and `reset`) do not create new commits, therefore post-rewrite hooks do
not need to handle them.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows for rebases to be run in parallel in separate worktrees
(think: interrupted in the middle of one rebase, being asked to perform
a different rebase, adding a separate worktree just for that job).
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>
Once upon a time, this here developer thought: wouldn't it be nice if,
say, Git for Windows' patches on top of core Git could be represented as
a thicket of branches, and be rebased on top of core Git in order to
maintain a cherry-pick'able set of patch series?
The original attempt to answer this was: git rebase --preserve-merges.
However, that experiment was never intended as an interactive option,
and it only piggy-backed on git rebase --interactive because that
command's implementation looked already very, very familiar: it was
designed by the same person who designed --preserve-merges: yours truly.
Some time later, some other developer (I am looking at you, Andreas!
;-)) decided that it would be a good idea to allow --preserve-merges to
be combined with --interactive (with caveats!) and the Git maintainer
(well, the interim Git maintainer during Junio's absence, that is)
agreed, and that is when the glamor of the --preserve-merges design
started to fall apart rather quickly and unglamorously.
The reason? In --preserve-merges mode, the parents of a merge commit (or
for that matter, of *any* commit) were not stated explicitly, but were
*implied* by the commit name passed to the `pick` command.
This made it impossible, for example, to reorder commits. Not to mention
to move commits between branches or, deity forbid, to split topic branches
into two.
Alas, these shortcomings also prevented that mode (whose original
purpose was to serve Git for Windows' needs, with the additional hope
that it may be useful to others, too) from serving Git for Windows'
needs.
Five years later, when it became really untenable to have one unwieldy,
big hodge-podge patch series of partly related, partly unrelated patches
in Git for Windows that was rebased onto core Git's tags from time to
time (earning the undeserved wrath of the developer of the ill-fated
git-remote-hg series that first obsoleted Git for Windows' competing
approach, only to be abandoned without maintainer later) was really
untenable, the "Git garden shears" were born [*1*/*2*]: a script,
piggy-backing on top of the interactive rebase, that would first
determine the branch topology of the patches to be rebased, create a
pseudo todo list for further editing, transform the result into a real
todo list (making heavy use of the `exec` command to "implement" the
missing todo list commands) and finally recreate the patch series on
top of the new base commit.
That was in 2013. And it took about three weeks to come up with the
design and implement it as an out-of-tree script. Needless to say, the
implementation needed quite a few years to stabilize, all the while the
design itself proved itself sound.
With this patch, the goodness of the Git garden shears comes to `git
rebase -i` itself. Passing the `--rebase-merges` option will generate
a todo list that can be understood readily, and where it is obvious
how to reorder commits. New branches can be introduced by inserting
`label` commands and calling `merge <label>`. And once this mode will
have become stable and universally accepted, we can deprecate the design
mistake that was `--preserve-merges`.
Link *1*:
https://github.com/msysgit/msysgit/blob/master/share/msysGit/shears.sh
Link *2*:
https://github.com/git-for-windows/build-extra/blob/master/shears.sh
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sequencer just learned new commands intended to recreate branch
structure (similar in spirit to --preserve-merges, but with a
substantially less-broken design).
Let's allow the rebase--helper to generate todo lists making use of
these commands, triggered by the new --rebase-merges option. For a
commit topology like this (where the HEAD points to C):
- A - B - C
\ /
D
the generated todo list would look like this:
# branch D
pick 0123 A
label branch-point
pick 1234 D
label D
reset branch-point
pick 2345 B
merge -C 3456 D # C
To keep things simple, we first only implement support for merge commits
with exactly two parents, leaving support for octopus merges to a later
patch series.
All merge-rebasing todo lists start with a hard-coded `label onto` line.
This makes it convenient to refer later on to the revision onto which
everything is rebased, e.g. as starting point for branches other than
the very first one.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Just like with regular `pick` commands, if we are trying to rebase a
merge commit, we now test whether the parents of said commit match HEAD
and the commits to be merged, and fast-forward if possible.
This is not only faster, but also avoids unnecessary proliferation of
new objects.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch is part of the effort to reimplement `--preserve-merges` with
a substantially improved design, a design that has been developed in the
Git for Windows project to maintain the dozens of Windows-specific patch
series on top of upstream Git.
The previous patch implemented the `label` and `reset` commands to label
commits and to reset to labeled commits. This patch adds the `merge`
command, with the following syntax:
merge [-C <commit>] <rev> # <oneline>
The <commit> parameter in this instance is the *original* merge commit,
whose author and message will be used for the merge commit that is about
to be created.
The <rev> parameter refers to the (possibly rewritten) revision to
merge. Let's see an example of a todo list (the initial `label onto`
command is an auto-generated convenience so that the label `onto` can be
used to refer to the revision onto which we rebase):
label onto
# Branch abc
reset onto
pick deadbeef Hello, world!
label abc
reset onto
pick cafecafe And now for something completely different
merge -C baaabaaa abc # Merge the branch 'abc' into master
To edit the merge commit's message (a "reword" for merges, if you will),
use `-c` (lower-case) instead of `-C`; this convention was borrowed from
`git commit` that also supports `-c` and `-C` with similar meanings.
To create *new* merges, i.e. without copying the commit message from an
existing commit, simply omit the `-C <commit>` parameter (which will
open an editor for the merge message):
merge abc
This comes in handy when splitting a branch into two or more branches.
Note: this patch only adds support for recursive merges, to keep things
simple. Support for octopus merges will be added later in a separate
patch series, support for merges using strategies other than the
recursive merge is left for the future.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the upcoming commits, we will teach the sequencer to rebase merges.
This will be done in a very different way from the unfortunate design of
`git rebase --preserve-merges` (which does not allow for reordering
commits, or changing the branch topology).
The main idea is to introduce new todo list commands, to support
labeling the current revision with a given name, resetting the current
revision to a previous state, and merging labeled revisions.
This idea was developed in Git for Windows' Git garden shears (that are
used to maintain Git for Windows' "thicket of branches" on top of
upstream Git), and this patch is part of the effort to make it available
to a wider audience, as well as to make the entire process more robust
(by implementing it in a safe and portable language rather than a Unix
shell script).
This commit implements the commands to label, and to reset to, given
revisions. The syntax is:
label <name>
reset <name>
Internally, the `label <name>` command creates the ref
`refs/rewritten/<name>`. This makes it possible to work with the labeled
revisions interactively, or in a scripted fashion (e.g. via the todo
list command `exec`).
These temporary refs are removed upon sequencer_remove_state(), so that
even a `git rebase --abort` cleans them up.
We disallow '#' as label because that character will be used as separator
in the upcoming `merge` command.
Later in this patch series, we will mark the `refs/rewritten/` refs as
worktree-local, to allow for interactive rebases to be run in parallel in
worktrees linked to the same repository.
As typos happen, a failed `label` or `reset` command will be rescheduled
immediately. As the previous code to reschedule a command is embedded
deeply in the pick/fixup/squash code path, we simply duplicate the few
lines. This will allow us to extend the new code path easily for the
upcoming `merge` command.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Up to now each command took a commit as its first argument and ignored
the rest of the line (usually the subject of the commit)
Now that we are about to introduce commands that take different
arguments, clarify each command by giving the argument list.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, we did that just magically, and potentially left some users
quite puzzled. Let's err on the safe side instead, telling the user what
is happening, and how they are supposed to continue.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, we did a lot of arithmetic gymnastics to get at the line in
the todo list (as stored in todo_list.buf). This might have been fast,
but only in terms of execution speed, not in terms of developer time.
Let's refactor this to make it a lot easier to read, and hence to
reason about the correctness of the code. It is not performance-critical
code anyway.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are some commands that have to be skipped from rearranging by virtue
of not handling any commits.
However, the logic was not quite obvious: it skipped commands based on
their position in the enum todo_command.
Instead, let's make it explicit that we skip all commands that do not
handle any commit. With one exception: the `drop` command, because it,
well, drops the commit and is therefore not eligible to rearranging.
Note: this is a bit academic at the moment because the only time we call
`rearrange_squash()` is directly after generating the todo list, when we
have nothing but `pick` commands anyway.
However, the upcoming `merge` command *will* want to be handled by that
function, and it *can* handle commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As pointed out in a review of the `--rebase-merges` patch series,
`rollback_lock_file()` clobbers errno. Therefore, we have to report the
error message that uses errno before calling said function.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An reusable "memory pool" implementation has been extracted from
fast-import.c, which in turn has become the first user of the
mem-pool API.
* jm/mem-pool:
mem-pool: move reusable parts of memory pool into its own file
fast-import: introduce mem_pool type
fast-import: rename mem_pool type to mp_block
Rename bunch of source files to more consistently use dashes
instead of underscores to connect words.
* sb/filenames-with-dashes:
replace_object.c: rename to use dash in file name
sha1_file.c: rename to use dash in file name
sha1_name.c: rename to use dash in file name
exec_cmd: rename to use dash in file name
unicode_width.h: rename to use dash in file name
write_or_die.c: rename to use dashes in file name
The index file is updated to record the fsmonitor section after a
full scan was made, to avoid wasting the effort that has already
spent.
* bp/fsmonitor-prime-index:
fsmonitor: force index write after full scan
Fix an unexploitable (because the oversized contents are not under
attacker's control) buffer overflow.
* bp/fsmonitor-bufsize-fix:
fsmonitor: fix incorrect buffer size when printing version number
Shell completion (in contrib) that gives list of paths have been
optimized somewhat.
* cb/bash-completion-ls-files-processing:
completion: improve ls-files filter performance
API clean-up aournd ref-filter code.
* jk/ref-array-push:
ref-filter: factor ref_array pushing into its own function
ref-filter: make ref_array_item allocation more consistent
ref-filter: use "struct object_id" consistently
Recent introduction of "--log-destination" option to "git daemon"
did not work well when the daemon was run under "--inetd" mode.
* lw/daemon-log-destination:
daemon.c: fix condition for redirecting stderr
"git branch --list" during an interrupted "rebase -i" now lets
users distinguish the case where a detached HEAD is being rebased
and a normal branch is being rebased.
* ks/branch-list-detached-rebase-i:
t3200: verify "branch --list" sanity when rebasing from detached HEAD
branch --list: print useful info whilst interactive rebasing a detached HEAD
"cd sub/dir && git commit ../path" ought to record the changes to
the file "sub/path", but this regressed long time ago.
* bw/commit-partial-from-subdirectory-fix:
commit: allow partial commits with relative paths
Some codepaths, including the refs API, get and keep relative
paths, that go out of sync when the process does chdir(2). The
chdir-notify API is introduced to let these codepaths adjust these
cached paths to the new current directory.
* jk/relative-directory-fix:
refs: use chdir_notify to update cached relative paths
set_work_tree: use chdir_notify
add chdir-notify API
trace.c: export trace_setup_key
set_git_dir: die when setenv() fails
"git rebase" has learned to honor "--signoff" option when using
backends other than "am" (but not "--preserve-merges").
* pw/rebase-signoff:
rebase --keep-empty: always use interactive rebase
rebase -p: error out if --signoff is given
rebase: extend --signoff support
"git rebase --keep-empty" still removed an empty commit if the
other side contained an empty commit (due to the "does an
equivalent patch exist already?" check), which has been corrected.
* pw/rebase-keep-empty-fixes:
rebase: respect --no-keep-empty
rebase -i --keep-empty: don't prune empty commits
rebase --root: stop assuming squash_onto is unset
"git gui" has been taught to work with old versions of tk (like
8.5.7) that do not support "ttk::style theme use" as a way to query
the current theme.
* cb/git-gui-ttk-style:
git-gui: workaround ttk:style theme use
"git gui" performs commit upon CTRL/CMD+ENTER but the
CTRL/CMD+KP_ENTER (i.e. enter key on the numpad) did not have the
same key binding. It now does.
* bp/git-gui-bind-kp-enter:
git-gui: bind CTRL/CMD+numpad ENTER to do_commit
Johannes Schindelin
Todd Zullinger
Phillip Wood
Stefan Beller
Junio C Hamano