These were last bumped in commit 92c57e5c1d (bump rename limit
defaults (again), 2011-02-19), and were bumped both because processors
had gotten faster, and because people were getting ugly merges that
caused problems and reporting it to the mailing list (suggesting that
folks were willing to spend more time waiting).
Since that time:
* Linus has continued recommending kernel folks to set
diff.renameLimit=0 (maps to 32767, currently)
* Folks with repositories with lots of renames were happy to set
merge.renameLimit above 32767, once the code supported that, to
get correct cherry-picks
* Processors have gotten faster
* It has been discovered that the timing methodology used last time
probably used too large example files.
The last point is probably worth explaining a bit more:
* The "average" file size used appears to have been average blob size
in the linux kernel history at the time (probably v2.6.25 or
something close to it).
* Since bigger files are modified more frequently, such a computation
weights towards larger files.
* Larger files may be more likely to be modified over time, but are
not more likely to be renamed -- the mean and median blob size
within a tree are a bit higher than the mean and median of blob
sizes in the history leading up to that version for the linux
kernel.
* The mean blob size in v2.6.25 was half the average blob size in
history leading to that point
* The median blob size in v2.6.25 was about 40% of the mean blob size
in v2.6.25.
* Since the mean blob size is more than double the median blob size,
any file as big as the mean will not be compared to any files of
median size or less (because they'd be more than 50% dissimilar).
* Since it is the number of files compared that provides the O(n^2)
behavior, median-sized files should matter more than mean-sized
ones.
The combined effect of the above is that the file size used in past
calculations was likely about 5x too large. Combine that with a CPU
performance improvement of ~30%, and we can increase the limits by
a factor of sqrt(5/(1-.3)) = 2.67, while keeping the original stated
time limits.
Keeping the same approximate time limit probably makes sense for
diff.renameLimit (there is no progress feedback in e.g. git log -p),
but the experience above suggests merge.renameLimit could be extended
significantly. In fact, it probably would make sense to have an
unlimited default setting for merge.renameLimit, but that would
likely need to be coupled with changes to how progress is displayed.
(See https://lore.kernel.org/git/YOx+Ok%2FEYvLqRMzJ@coredump.intra.peff.net/
for details in that area.) For now, let's just bump the approximate
time limit from 10s to 1m.
(Note: We do not want to use actual time limits, because getting results
that depend on how loaded your system is that day feels bad, and because
we don't discover that we won't get all the renames until after we've
put in a lot of work rather than just upfront telling the user there are
too many files involved.)
Using the original time limit of 2s for diff.renameLimit, and bumping
merge.renameLimit from 10s to 60s, I found the following timings using
the simple script at the end of this commit message (on an AWS c5.xlarge
which reports as "Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz"):
N Timing
1300 1.995s
7100 59.973s
So let's round down to nice even numbers and bump the limits from
400->1000, and from 1000->7000.
Here is the measure_rename_perf script (adapted from
https://lore.kernel.org/git/20080211113516.GB6344@coredump.intra.peff.net/
in particular to avoid triggering the linear handling from
basename-guided rename detection):
#!/bin/bash
n=$1; shift
rm -rf repo
mkdir repo && cd repo
git init -q -b main
mkdata() {
mkdir $1
for i in `seq 1 $2`; do
(sed "s/^/$i /" <../sample
echo tag: $1
) >$1/$i
done
}
mkdata initial $n
git add .
git commit -q -m initial
mkdata new $n
git add .
cd new
for i in *; do git mv $i $i.renamed; done
cd ..
git rm -q -rf initial
git commit -q -m new
time git diff-tree -M -l0 --summary HEAD^ HEAD
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A few places in the docs implied that rename/copy detection is always
quadratic or that all (unpaired) files were involved in the quadratic
portion of rename/copy detection. The following two commits each
introduced an exception to this:
9027f53cb5 (Do linear-time/space rename logic for exact renames,
2007-10-25)
bd24aa2f97 (diffcore-rename: guide inexact rename detection based
on basenames, 2021-02-14)
(As a side note, for copy detection, the basename guided inexact rename
detection is turned off and the exact renames will only result in
sources (without the dests) being removed from the set of files used in
quadratic detection. So, for copy detection, the documentation was
closer to correct.)
Avoid implying that all files involved in rename/copy detection are
subject to the full quadratic algorithm. While at it, also note the
default values for all these settings.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit a01f7f2ba0 (merge: enable defaulttoupstream by default,
2014-04-20) forgot to mention the new default in the configuration
documentation.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In rebase, one can pass the `--autostash` option to cause the worktree
to be automatically stashed before continuing with the rebase. This
option is missing in merge, however.
Implement the `--autostash` option and corresponding `merge.autoStash`
option in merge which stashes before merging and then pops after.
This option is useful when a developer has some local changes on a topic
branch but they realize that their work depends on another branch.
Previously, they had to run something like
git fetch ...
git stash push
git merge FETCH_HEAD
git stash pop
but now, that is reduced to
git fetch ...
git merge --autostash FETCH_HEAD
When an autostash is generated, it is automatically reapplied to the
worktree only in three explicit situations:
1. An incomplete merge is commit using `git commit`.
2. A merge completes successfully.
3. A merge is aborted using `git merge --abort`.
In all other situations where the merge state is removed using
remove_merge_branch_state() such as aborting a merge via
`git reset --hard`, the autostash is saved into the stash reflog
instead keeping the worktree clean.
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Suggested-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When all of x/a, x/b, and x/c have moved to z/a, z/b, and z/c on one
branch, there is a question about whether x/d added on a different
branch should remain at x/d or appear at z/d when the two branches are
merged. There are different possible viewpoints here:
A) The file was placed at x/d; it's unrelated to the other files in
x/ so it doesn't matter that all the files from x/ moved to z/ on
one branch; x/d should still remain at x/d.
B) x/d is related to the other files in x/, and x/ was renamed to z/;
therefore x/d should be moved to z/d.
Since there was no ability to detect directory renames prior to
git-2.18, users experienced (A) regardless of context. Choice (B) was
implemented in git-2.18, with no option to go back to (A), and has been
in use since. However, one user reported that the merge results did not
match their expectations, making the change of default problematic,
especially since there was no notice printed when directory rename
detection moved files.
Note that there is also a third possibility here:
C) There are different answers depending on the context and content
that cannot be determined by git, so this is a conflict. Use a
higher stage in the index to record the conflict and notify the
user of the potential issue instead of silently selecting a
resolution for them.
Add an option for users to specify their preference for whether to use
directory rename detection, and default to (C). Even when directory
rename detection is on, add notice messages about files moved into new
directories.
As a sidenote, x/d did not have to be a new file here; it could have
already existed at some other path and been renamed to x/d, with
directory rename detection just renaming it again to z/d. Thus, it's
not just new files, but also a modification to all rename types (normal
renames, rename/add, rename/delete, rename/rename(1to1),
rename/rename(1to2), and rename/rename(2to1)).
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Note that this file is not directly included in config.txt but through
merge-config.txt and it's in "merge" section instead of a separate
"fmtMergeMsg" section like others.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the ability to control rename detection for merge via a config setting.
This setting behaves the same and defaults to the value of diff.renames but only
applies to merge.
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update the documentation to better indicate that the renameLimit setting is
ignored if rename detection is turned off via command line options or config
settings.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git merge --verify-signatures can be used to verify that the tip commit
of the branch being merged in is properly signed, but it's cumbersome to
have to specify that every time.
Add a configuration option that enables this behaviour by default, which
can be overridden by --no-verify-signatures.
Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This change GIT_* variables that where in italic style to monospaced font
according to the guideline. It was obtained with
perl -pi -e "s/\'(GIT_.*?)\'/\`\1\`/g" *.txt
One of the main purposes is to stick to the CodingGuidelines as possible so
that people writting new documentation by mimicking the existing are more likely
to have it right (even if they didn't read the CodingGuidelines).
Signed-off-by: Tom Russello <tom.russello@grenoble-inp.org>
Signed-off-by: Erwan Mathoniere <erwan.mathoniere@grenoble-inp.org>
Signed-off-by: Samuel Groot <samuel.groot@grenoble-inp.org>
Signed-off-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'merge.branchdesc' is only mentioned in the docs of 'git fmt-merge-msg'.
The description of 'merge.log' is already duplicated between
'merge-config.txt' and 'git-fmt-merge-msg.txt'; instead of duplicating the
description of another config variable, extract the descriptions of both
of these variables from 'git-fmt-merge-msg.txt' into a separate file and
include it there and in 'merge-config.txt'.
Leave 'merge.summary' only in git-fmt-merge-msg.txt, as it is marked
as deprecated.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This should improve readability. Compare "thislongname" and
"thisLongName". The following keys are left in unchanged. We can
decide what to do with them later.
- am.keepcr
- core.autocrlf .safecrlf .trustctime
- diff.dirstat .noprefix
- gitcvs.usecrlfattr
- gui.blamehistoryctx .trustmtime
- pull.twohead
- receive.autogc
- sendemail.signedoffbycc .smtpsslcertpath .suppresscc
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the show_tool_names() function to build lists of all
the built-in tools supported by difftool and mergetool.
This frees us from needing to update the documentation
whenever a new tool is added.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This change was already done by 0e615b252f (Matthieu Moy, Tue Nov 2
2010, Replace "remote tracking" with "remote-tracking"), but new
instances of remote tracking (without dash) were introduced in the
meantime.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Jeff King <peff@peff.net>
This variable gives the default setting for --ff, --no-ff or --ff-only
options of "git merge" command.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git merge" without specifying any commit is a no-op by default.
A new option merge.defaultupstream can be set to true to cause such an
invocation of the command to merge the upstream branches configured for
the current branch by using their last observed values stored in their
remote tracking branches.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Tested-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Tested-by: Chris Packham <judge.packham@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make 'merge.log' an integer or boolean option to set the number of
shortlog entries to display in the merge commit. Note that it defaults
to false, and that true means a default value of 20. Also update
corresponding documentation.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Thanks-to: Jonathan Nieder <jrnieder@gmail.com>
Thanks-to: Johannes Sixt <j.sixt@viscovery.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, merging across changes in line ending normalization is
painful since files containing CRLF will conflict with normalized files,
even if the only difference between the two versions is the line
endings. Additionally, any "real" merge conflicts that exist are
obscured because every line in the file has a conflict.
Assume you start out with a repo that has a lot of text files with CRLF
checked in (A):
o---C
/ \
A---B---D
B: Add "* text=auto" to .gitattributes and normalize all files to
LF-only
C: Modify some of the text files
D: Try to merge C
You will get a ridiculous number of LF/CRLF conflicts when trying to
merge C into D, since the repository contents for C are "wrong" wrt the
new .gitattributes file.
Fix ll-merge so that the "base", "theirs" and "ours" stages are passed
through convert_to_worktree() and convert_to_git() before a three-way
merge. This ensures that all three stages are normalized in the same
way, removing from consideration differences that are only due to
normalization.
This feature is optional for now since it changes a low-level mechanism
and is not necessary for the majority of users. The "merge.renormalize"
config variable enables it.
Signed-off-by: Eyvind Bernhardsen <eyvind.bernhardsen@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add p4merge to the set of built-in diff/merge tools, and update
bash completion and documentation.
Signed-off-by: Scott Chacon <schacon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Araxis merge is now a built-in diff/merge tool.
This adds araxis to git-completion and updates
the documentation to mention araxis.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This adds diffuse as a built-in merge tool.
Signed-off-by: Sebastian Pipping <sebastian@pipping.org>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
TortoiseMerge comes with TortoiseSVN or TortoiseGit for Windows. It can
only be used as a merge tool with an existing base file. It cannot be
used without a base nor as a diff tool.
The documentation only mentions the slash '/' as command line option
prefix, which refused to work, but the parser also accepts the dash '-'
See http://code.google.com/p/msysgit/issues/detail?id=226
Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Improve some minor language and format issues like hyphenation,
phrases, spacing, word order, comma, attributes.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of rename limiting is to bound the amount of time
we spend figuring out inexact renames. Currently we use a
single value, diff.renamelimit, for all situations. However,
it is probably the case that a user is willing to spend more
time finding renames during a merge than they are while
looking at git-log.
This patch provides a way of setting those values separately
(though for backwards compatibility, merge still falls back
on the diff renamelimit).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are new synonyms to the '--(no-)summary' option and the
'merge.summary' config variable, but are consistent with the soon to be
added 'merge --(no-)log' options. The 'merge.summary' config variable and
'--(no-)summary' options are still accepted, but are advertised to be
removed in the future.
'merge.log' takes precedence over 'merge.summary' if they are both set
inconsistently.
Update documentation and tests accordingly.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This variable has the same effect, as 'merge.diffstat'.
Also mention it in the documentation.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Include the new file from config.txt and git-merge.txt.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Elijah Newren