|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | GIT URLS | REMOTES | MERGE STRATEGIES | DEFAULT BEHAVIOUR | EXAMPLES | SECURITY | BUGS | SEE ALSO | GIT | COLOPHON |
|
|
|
GIT-PULL(1) Git Manual GIT-PULL(1)
git-pull - Fetch from and integrate with another repository or a
local branch
git pull [<options>] [<repository> [<refspec>...]]
Incorporates changes from a remote repository into the current
branch. If the current branch is behind the remote, then by
default it will fast-forward the current branch to match the
remote. If the current branch and the remote have diverged, the
user needs to specify how to reconcile the divergent branches
with --rebase or --no-rebase (or the corresponding configuration
option in pull.rebase).
More precisely, git pull runs git fetch with the given parameters
and then depending on configuration options or command line
flags, will call either git rebase or git merge to reconcile
diverging branches.
<repository> should be the name of a remote repository as passed
to git-fetch(1). <refspec> can name an arbitrary remote ref (for
example, the name of a tag) or even a collection of refs with
corresponding remote-tracking branches (e.g.,
refs/heads/*:refs/remotes/origin/*), but usually it is the name
of a branch in the remote repository.
Default values for <repository> and <branch> are read from the
"remote" and "merge" configuration for the current branch as set
by git-branch(1) --track.
Assume the following history exists and the current branch is
"master":
A---B---C master on origin
/
D---E---F---G master
^
origin/master in your repository
Then "git pull" will fetch and replay the changes from the remote
master branch since it diverged from the local master (i.e., E)
until its current commit (C) on top of master and record the
result in a new commit along with the names of the two parent
commits and a log message from the user describing the changes.
A---B---C origin/master
/ \
D---E---F---G---H master
See git-merge(1) for details, including how conflicts are
presented and handled.
In Git 1.7.0 or later, to cancel a conflicting merge, use git
reset --merge. Warning: In older versions of Git, running git
pull with uncommitted changes is discouraged: while possible, it
leaves you in a state that may be hard to back out of in the case
of a conflict.
If any of the remote changes overlap with local uncommitted
changes, the merge will be automatically canceled and the work
tree untouched. It is generally best to get any local changes in
working order before pulling or stash them away with
git-stash(1).
-q, --quiet
This is passed to both underlying git-fetch to squelch
reporting of during transfer, and underlying git-merge to
squelch output during merging.
-v, --verbose
Pass --verbose to git-fetch and git-merge.
--[no-]recurse-submodules[=(yes|on-demand|no)]
This option controls if new commits of populated submodules
should be fetched, and if the working trees of active
submodules should be updated, too (see git-fetch(1),
git-config(1) and gitmodules(5)).
If the checkout is done via rebase, local submodule commits
are rebased as well.
If the update is done via merge, the submodule conflicts are
resolved and checked out.
Options related to merging
--commit, --no-commit
Perform the merge and commit the result. This option can be
used to override --no-commit. Only useful when merging.
With --no-commit perform the merge and stop just before
creating a merge commit, to give the user a chance to inspect
and further tweak the merge result before committing.
Note that fast-forward updates do not create a merge commit
and therefore there is no way to stop those merges with
--no-commit. Thus, if you want to ensure your branch is not
changed or updated by the merge command, use --no-ff with
--no-commit.
--edit, -e, --no-edit
Invoke an editor before committing successful mechanical
merge to further edit the auto-generated merge message, so
that the user can explain and justify the merge. The
--no-edit option can be used to accept the auto-generated
message (this is generally discouraged).
Older scripts may depend on the historical behaviour of not
allowing the user to edit the merge log message. They will
see an editor opened when they run git merge. To make it
easier to adjust such scripts to the updated behaviour, the
environment variable GIT_MERGE_AUTOEDIT can be set to no at
the beginning of them.
--cleanup=<mode>
This option determines how the merge message will be cleaned
up before committing. See git-commit(1) for more details. In
addition, if the <mode> is given a value of scissors,
scissors will be appended to MERGE_MSG before being passed on
to the commit machinery in the case of a merge conflict.
--ff-only
Only update to the new history if there is no divergent local
history. This is the default when no method for reconciling
divergent histories is provided (via the --rebase=* flags).
--ff, --no-ff
When merging rather than rebasing, specifies how a merge is
handled when the merged-in history is already a descendant of
the current history. If merging is requested, --ff is the
default unless merging an annotated (and possibly signed) tag
that is not stored in its natural place in the refs/tags/
hierarchy, in which case --no-ff is assumed.
With --ff, when possible resolve the merge as a fast-forward
(only update the branch pointer to match the merged branch;
do not create a merge commit). When not possible (when the
merged-in history is not a descendant of the current
history), create a merge commit.
With --no-ff, create a merge commit in all cases, even when
the merge could instead be resolved as a fast-forward.
-S[<keyid>], --gpg-sign[=<keyid>], --no-gpg-sign
GPG-sign the resulting merge commit. The keyid argument is
optional and defaults to the committer identity; if
specified, it must be stuck to the option without a space.
--no-gpg-sign is useful to countermand both commit.gpgSign
configuration variable, and earlier --gpg-sign.
--log[=<n>], --no-log
In addition to branch names, populate the log message with
one-line descriptions from at most <n> actual commits that
are being merged. See also git-fmt-merge-msg(1). Only useful
when merging.
With --no-log do not list one-line descriptions from the
actual commits being merged.
--signoff, --no-signoff
Add a Signed-off-by trailer by the committer at the end of
the commit log message. The meaning of a signoff depends on
the project to which you’re committing. For example, it may
certify that the committer has the rights to submit the work
under the project’s license or agrees to some contributor
representation, such as a Developer Certificate of Origin.
(See https://developercertificate.org for the one used by the
Linux kernel and Git projects.) Consult the documentation or
leadership of the project to which you’re contributing to
understand how the signoffs are used in that project.
The --no-signoff option can be used to countermand an earlier
--signoff option on the command line.
--stat, -n, --no-stat
Show a diffstat at the end of the merge. The diffstat is also
controlled by the configuration option merge.stat.
With -n or --no-stat do not show a diffstat at the end of the
merge.
--squash, --no-squash
Produce the working tree and index state as if a real merge
happened (except for the merge information), but do not
actually make a commit, move the HEAD, or record
$GIT_DIR/MERGE_HEAD (to cause the next git commit command to
create a merge commit). This allows you to create a single
commit on top of the current branch whose effect is the same
as merging another branch (or more in case of an octopus).
With --no-squash perform the merge and commit the result.
This option can be used to override --squash.
With --squash, --commit is not allowed, and will fail.
Only useful when merging.
--[no-]verify
By default, the pre-merge and commit-msg hooks are run. When
--no-verify is given, these are bypassed. See also
githooks(5). Only useful when merging.
-s <strategy>, --strategy=<strategy>
Use the given merge strategy; can be supplied more than once
to specify them in the order they should be tried. If there
is no -s option, a built-in list of strategies is used
instead (ort when merging a single head, octopus otherwise).
-X <option>, --strategy-option=<option>
Pass merge strategy specific option through to the merge
strategy.
--verify-signatures, --no-verify-signatures
Verify that the tip commit of the side branch being merged is
signed with a valid key, i.e. a key that has a valid uid: in
the default trust model, this means the signing key has been
signed by a trusted key. If the tip commit of the side branch
is not signed with a valid key, the merge is aborted.
Only useful when merging.
--summary, --no-summary
Synonyms to --stat and --no-stat; these are deprecated and
will be removed in the future.
--autostash, --no-autostash
Automatically create a temporary stash entry before the
operation begins, record it in the ref MERGE_AUTOSTASH and
apply it after the operation ends. This means that you can
run the operation on a dirty worktree. However, use with
care: the final stash application after a successful merge
might result in non-trivial conflicts.
--allow-unrelated-histories
By default, git merge command refuses to merge histories that
do not share a common ancestor. This option can be used to
override this safety when merging histories of two projects
that started their lives independently. As that is a very
rare occasion, no configuration variable to enable this by
default exists and will not be added.
Only useful when merging.
-r, --rebase[=(false|true|merges|interactive)]
When true, rebase the current branch on top of the upstream
branch after fetching. If there is a remote-tracking branch
corresponding to the upstream branch and the upstream branch
was rebased since last fetched, the rebase uses that
information to avoid rebasing non-local changes.
When set to merges, rebase using git rebase --rebase-merges
so that the local merge commits are included in the rebase
(see git-rebase(1) for details).
When false, merge the upstream branch into the current
branch.
When interactive, enable the interactive mode of rebase.
See pull.rebase, branch.<name>.rebase and
branch.autoSetupRebase in git-config(1) if you want to make
git pull always use --rebase instead of merging.
Note
This is a potentially dangerous mode of operation. It
rewrites history, which does not bode well when you
published that history already. Do not use this option
unless you have read git-rebase(1) carefully.
--no-rebase
This is shorthand for --rebase=false.
Options related to fetching
--[no-]all
Fetch all remotes. This overrides the configuration variable
fetch.all.
-a, --append
Append ref names and object names of fetched refs to the
existing contents of .git/FETCH_HEAD. Without this option old
data in .git/FETCH_HEAD will be overwritten.
--atomic
Use an atomic transaction to update local refs. Either all
refs are updated, or on error, no refs are updated.
--depth=<depth>
Limit fetching to the specified number of commits from the
tip of each remote branch history. If fetching to a shallow
repository created by git clone with --depth=<depth> option
(see git-clone(1)), deepen or shorten the history to the
specified number of commits. Tags for the deepened commits
are not fetched.
--deepen=<depth>
Similar to --depth, except it specifies the number of commits
from the current shallow boundary instead of from the tip of
each remote branch history.
--shallow-since=<date>
Deepen or shorten the history of a shallow repository to
include all reachable commits after <date>.
--shallow-exclude=<revision>
Deepen or shorten the history of a shallow repository to
exclude commits reachable from a specified remote branch or
tag. This option can be specified multiple times.
--unshallow
If the source repository is complete, convert a shallow
repository to a complete one, removing all the limitations
imposed by shallow repositories.
If the source repository is shallow, fetch as much as
possible so that the current repository has the same history
as the source repository.
--update-shallow
By default when fetching from a shallow repository, git fetch
refuses refs that require updating .git/shallow. This option
updates .git/shallow and accepts such refs.
--negotiation-tip=<commit|glob>
By default, Git will report, to the server, commits reachable
from all local refs to find common commits in an attempt to
reduce the size of the to-be-received packfile. If specified,
Git will only report commits reachable from the given tips.
This is useful to speed up fetches when the user knows which
local ref is likely to have commits in common with the
upstream ref being fetched.
This option may be specified more than once; if so, Git will
report commits reachable from any of the given commits.
The argument to this option may be a glob on ref names, a
ref, or the (possibly abbreviated) SHA-1 of a commit.
Specifying a glob is equivalent to specifying this option
multiple times, one for each matching ref name.
See also the fetch.negotiationAlgorithm and push.negotiate
configuration variables documented in git-config(1), and the
--negotiate-only option below.
--negotiate-only
Do not fetch anything from the server, and instead print the
ancestors of the provided --negotiation-tip=* arguments,
which we have in common with the server.
This is incompatible with
--recurse-submodules=[yes|on-demand]. Internally this is used
to implement the push.negotiate option, see git-config(1).
--dry-run
Show what would be done, without making any changes.
--porcelain
Print the output to standard output in an easy-to-parse
format for scripts. See section OUTPUT in git-fetch(1) for
details.
This is incompatible with
--recurse-submodules=[yes|on-demand] and takes precedence
over the fetch.output config option.
-f, --force
When git fetch is used with <src>:<dst> refspec, it may
refuse to update the local branch as discussed in the
<refspec> part of the git-fetch(1) documentation. This option
overrides that check.
-k, --keep
Keep downloaded pack.
--prefetch
Modify the configured refspec to place all refs into the
refs/prefetch/ namespace. See the prefetch task in
git-maintenance(1).
-p, --prune
Before fetching, remove any remote-tracking references that
no longer exist on the remote. Tags are not subject to
pruning if they are fetched only because of the default tag
auto-following or due to a --tags option. However, if tags
are fetched due to an explicit refspec (either on the command
line or in the remote configuration, for example if the
remote was cloned with the --mirror option), then they are
also subject to pruning. Supplying --prune-tags is a
shorthand for providing the tag refspec.
--no-tags
By default, tags that point at objects that are downloaded
from the remote repository are fetched and stored locally.
This option disables this automatic tag following. The
default behavior for a remote may be specified with the
remote.<name>.tagOpt setting. See git-config(1).
--refmap=<refspec>
When fetching refs listed on the command line, use the
specified refspec (can be given more than once) to map the
refs to remote-tracking branches, instead of the values of
remote.*.fetch configuration variables for the remote
repository. Providing an empty <refspec> to the --refmap
option causes Git to ignore the configured refspecs and rely
entirely on the refspecs supplied as command-line arguments.
See section on "Configured Remote-tracking Branches" for
details.
-t, --tags
Fetch all tags from the remote (i.e., fetch remote tags
refs/tags/* into local tags with the same name), in addition
to whatever else would otherwise be fetched. Using this
option alone does not subject tags to pruning, even if
--prune is used (though tags may be pruned anyway if they are
also the destination of an explicit refspec; see --prune).
-j, --jobs=<n>
Number of parallel children to be used for all forms of
fetching.
If the --multiple option was specified, the different remotes
will be fetched in parallel. If multiple submodules are
fetched, they will be fetched in parallel. To control them
independently, use the config settings fetch.parallel and
submodule.fetchJobs (see git-config(1)).
Typically, parallel recursive and multi-remote fetches will
be faster. By default fetches are performed sequentially, not
in parallel.
--set-upstream
If the remote is fetched successfully, add upstream
(tracking) reference, used by argument-less git-pull(1) and
other commands. For more information, see branch.<name>.merge
and branch.<name>.remote in git-config(1).
--upload-pack <upload-pack>
When given, and the repository to fetch from is handled by
git fetch-pack, --exec=<upload-pack> is passed to the command
to specify non-default path for the command run on the other
end.
--progress
Progress status is reported on the standard error stream by
default when it is attached to a terminal, unless -q is
specified. This flag forces progress status even if the
standard error stream is not directed to a terminal.
-o <option>, --server-option=<option>
Transmit the given string to the server when communicating
using protocol version 2. The given string must not contain a
NUL or LF character. The server’s handling of server options,
including unknown ones, is server-specific. When multiple
--server-option=<option> are given, they are all sent to the
other side in the order listed on the command line.
--show-forced-updates
By default, git checks if a branch is force-updated during
fetch. This can be disabled through fetch.showForcedUpdates,
but the --show-forced-updates option guarantees this check
occurs. See git-config(1).
--no-show-forced-updates
By default, git checks if a branch is force-updated during
fetch. Pass --no-show-forced-updates or set
fetch.showForcedUpdates to false to skip this check for
performance reasons. If used during git-pull the --ff-only
option will still check for forced updates before attempting
a fast-forward update. See git-config(1).
-4, --ipv4
Use IPv4 addresses only, ignoring IPv6 addresses.
-6, --ipv6
Use IPv6 addresses only, ignoring IPv4 addresses.
<repository>
The "remote" repository that is the source of a fetch or pull
operation. This parameter can be either a URL (see the
section GIT URLS below) or the name of a remote (see the
section REMOTES below).
<refspec>
Specifies which refs to fetch and which local refs to update.
When no <refspec>s appear on the command line, the refs to
fetch are read from remote.<repository>.fetch variables
instead (see the section "CONFIGURED REMOTE-TRACKING
BRANCHES" in git-fetch(1)).
The format of a <refspec> parameter is an optional plus +,
followed by the source <src>, followed by a colon :, followed
by the destination ref <dst>. The colon can be omitted when
<dst> is empty. <src> is typically a ref, but it can also be
a fully spelled hex object name.
A <refspec> may contain a * in its <src> to indicate a simple
pattern match. Such a refspec functions like a glob that
matches any ref with the same prefix. A pattern <refspec>
must have a * in both the <src> and <dst>. It will map refs
to the destination by replacing the * with the contents
matched from the source.
If a refspec is prefixed by ^, it will be interpreted as a
negative refspec. Rather than specifying which refs to fetch
or which local refs to update, such a refspec will instead
specify refs to exclude. A ref will be considered to match if
it matches at least one positive refspec, and does not match
any negative refspec. Negative refspecs can be useful to
restrict the scope of a pattern refspec so that it will not
include specific refs. Negative refspecs can themselves be
pattern refspecs. However, they may only contain a <src> and
do not specify a <dst>. Fully spelled out hex object names
are also not supported.
tag <tag> means the same as refs/tags/<tag>:refs/tags/<tag>;
it requests fetching everything up to the given tag.
The remote ref that matches <src> is fetched, and if <dst> is
not an empty string, an attempt is made to update the local
ref that matches it.
Whether that update is allowed without --force depends on the
ref namespace it’s being fetched to, the type of object being
fetched, and whether the update is considered to be a
fast-forward. Generally, the same rules apply for fetching as
when pushing, see the <refspec>... section of git-push(1)
for what those are. Exceptions to those rules particular to
git fetch are noted below.
Until Git version 2.20, and unlike when pushing with
git-push(1), any updates to refs/tags/* would be accepted
without + in the refspec (or --force). When fetching, we
promiscuously considered all tag updates from a remote to be
forced fetches. Since Git version 2.20, fetching to update
refs/tags/* works the same way as when pushing. I.e. any
updates will be rejected without + in the refspec (or
--force).
Unlike when pushing with git-push(1), any updates outside of
refs/{tags,heads}/* will be accepted without + in the refspec
(or --force), whether that’s swapping e.g. a tree object for
a blob, or a commit for another commit that doesn’t have the
previous commit as an ancestor etc.
Unlike when pushing with git-push(1), there is no
configuration which’ll amend these rules, and nothing like a
pre-fetch hook analogous to the pre-receive hook.
As with pushing with git-push(1), all of the rules described
above about what’s not allowed as an update can be overridden
by adding an optional leading + to a refspec (or using the
--force command line option). The only exception to this is
that no amount of forcing will make the refs/heads/*
namespace accept a non-commit object.
Note
When the remote branch you want to fetch is known to be
rewound and rebased regularly, it is expected that its
new tip will not be a descendant of its previous tip (as
stored in your remote-tracking branch the last time you
fetched). You would want to use the + sign to indicate
non-fast-forward updates will be needed for such
branches. There is no way to determine or declare that a
branch will be made available in a repository with this
behavior; the pulling user simply must know this is the
expected usage pattern for a branch.
Note
There is a difference between listing multiple <refspec>
directly on git pull command line and having multiple
remote.<repository>.fetch entries in your configuration
for a <repository> and running a git pull command without
any explicit <refspec> parameters. <refspec>s listed
explicitly on the command line are always merged into the
current branch after fetching. In other words, if you
list more than one remote ref, git pull will create an
Octopus merge. On the other hand, if you do not list any
explicit <refspec> parameter on the command line, git
pull will fetch all the <refspec>s it finds in the
remote.<repository>.fetch configuration and merge only
the first <refspec> found into the current branch. This
is because making an Octopus from remote refs is rarely
done, while keeping track of multiple remote heads in
one-go by fetching more than one is often useful.
In general, URLs contain information about the transport
protocol, the address of the remote server, and the path to the
repository. Depending on the transport protocol, some of this
information may be absent.
Git supports ssh, git, http, and https protocols (in addition,
ftp and ftps can be used for fetching, but this is inefficient
and deprecated; do not use them).
The native transport (i.e. git:// URL) does no authentication and
should be used with caution on unsecured networks.
The following syntaxes may be used with them:
• ssh://[<user>@]<host>[:<port>]/<path-to-git-repo>
• git://<host>[:<port>]/<path-to-git-repo>
• http[s]://<host>[:<port>]/<path-to-git-repo>
• ftp[s]://<host>[:<port>]/<path-to-git-repo>
An alternative scp-like syntax may also be used with the ssh
protocol:
• [<user>@]<host>:/<path-to-git-repo>
This syntax is only recognized if there are no slashes before the
first colon. This helps differentiate a local path that contains
a colon. For example the local path foo:bar could be specified as
an absolute path or ./foo:bar to avoid being misinterpreted as an
ssh url.
The ssh and git protocols additionally support ~<username>
expansion:
• ssh://[<user>@]<host>[:<port>]/~<user>/<path-to-git-repo>
• git://<host>[:<port>]/~<user>/<path-to-git-repo>
• [<user>@]<host>:~<user>/<path-to-git-repo>
For local repositories, also supported by Git natively, the
following syntaxes may be used:
• /path/to/repo.git/
• file:///path/to/repo.git/
These two syntaxes are mostly equivalent, except when cloning,
when the former implies --local option. See git-clone(1) for
details.
git clone, git fetch and git pull, but not git push, will also
accept a suitable bundle file. See git-bundle(1).
When Git doesn’t know how to handle a certain transport protocol,
it attempts to use the remote-<transport> remote helper, if one
exists. To explicitly request a remote helper, the following
syntax may be used:
• <transport>::<address>
where <address> may be a path, a server and path, or an arbitrary
URL-like string recognized by the specific remote helper being
invoked. See gitremote-helpers(7) for details.
If there are a large number of similarly-named remote
repositories and you want to use a different format for them
(such that the URLs you use will be rewritten into URLs that
work), you can create a configuration section of the form:
[url "<actual-url-base>"]
insteadOf = <other-url-base>
For example, with this:
[url "git://git.host.xz/"]
insteadOf = host.xz:/path/to/
insteadOf = work:
a URL like "work:repo.git" or like "host.xz:/path/to/repo.git"
will be rewritten in any context that takes a URL to be
"git://git.host.xz/repo.git".
If you want to rewrite URLs for push only, you can create a
configuration section of the form:
[url "<actual-url-base>"]
pushInsteadOf = <other-url-base>
For example, with this:
[url "ssh://example.org/"]
pushInsteadOf = git://example.org/
a URL like "git://example.org/path/to/repo.git" will be rewritten
to "ssh://example.org/path/to/repo.git" for pushes, but pulls
will still use the original URL.
The name of one of the following can be used instead of a URL as
<repository> argument:
• a remote in the Git configuration file: $GIT_DIR/config,
• a file in the $GIT_DIR/remotes directory, or
• a file in the $GIT_DIR/branches directory.
All of these also allow you to omit the refspec from the command
line because they each contain a refspec which git will use by
default.
Named remote in configuration file
You can choose to provide the name of a remote which you had
previously configured using git-remote(1), git-config(1) or even
by a manual edit to the $GIT_DIR/config file. The URL of this
remote will be used to access the repository. The refspec of this
remote will be used by default when you do not provide a refspec
on the command line. The entry in the config file would appear
like this:
[remote "<name>"]
url = <URL>
pushurl = <pushurl>
push = <refspec>
fetch = <refspec>
The <pushurl> is used for pushes only. It is optional and
defaults to <URL>. Pushing to a remote affects all defined
pushurls or all defined urls if no pushurls are defined. Fetch,
however, will only fetch from the first defined url if multiple
urls are defined.
Named file in $GIT_DIR/remotes
You can choose to provide the name of a file in $GIT_DIR/remotes.
The URL in this file will be used to access the repository. The
refspec in this file will be used as default when you do not
provide a refspec on the command line. This file should have the
following format:
URL: one of the above URL formats
Push: <refspec>
Pull: <refspec>
Push: lines are used by git push and Pull: lines are used by git
pull and git fetch. Multiple Push: and Pull: lines may be
specified for additional branch mappings.
Named file in $GIT_DIR/branches
You can choose to provide the name of a file in
$GIT_DIR/branches. The URL in this file will be used to access
the repository. This file should have the following format:
<URL>#<head>
<URL> is required; #<head> is optional.
Depending on the operation, git will use one of the following
refspecs, if you don’t provide one on the command line. <branch>
is the name of this file in $GIT_DIR/branches and <head> defaults
to master.
git fetch uses:
refs/heads/<head>:refs/heads/<branch>
git push uses:
HEAD:refs/heads/<head>
The merge mechanism (git merge and git pull commands) allows the
backend merge strategies to be chosen with -s option. Some
strategies can also take their own options, which can be passed
by giving -X<option> arguments to git merge and/or git pull.
ort
This is the default merge strategy when pulling or merging
one branch. This strategy can only resolve two heads using a
3-way merge algorithm. When there is more than one common
ancestor that can be used for 3-way merge, it creates a
merged tree of the common ancestors and uses that as the
reference tree for the 3-way merge. This has been reported to
result in fewer merge conflicts without causing mismerges by
tests done on actual merge commits taken from Linux 2.6
kernel development history. Additionally this strategy can
detect and handle merges involving renames. It does not make
use of detected copies. The name for this algorithm is an
acronym ("Ostensibly Recursive’s Twin") and came from the
fact that it was written as a replacement for the previous
default algorithm, recursive.
The ort strategy can take the following options:
ours
This option forces conflicting hunks to be auto-resolved
cleanly by favoring our version. Changes from the other
tree that do not conflict with our side are reflected in
the merge result. For a binary file, the entire contents
are taken from our side.
This should not be confused with the ours merge strategy,
which does not even look at what the other tree contains
at all. It discards everything the other tree did,
declaring our history contains all that happened in it.
theirs
This is the opposite of ours; note that, unlike ours,
there is no theirs merge strategy to confuse this merge
option with.
ignore-space-change, ignore-all-space, ignore-space-at-eol,
ignore-cr-at-eol
Treats lines with the indicated type of whitespace change
as unchanged for the sake of a three-way merge.
Whitespace changes mixed with other changes to a line are
not ignored. See also git-diff(1) -b, -w,
--ignore-space-at-eol, and --ignore-cr-at-eol.
• If their version only introduces whitespace changes
to a line, our version is used;
• If our version introduces whitespace changes but
their version includes a substantial change, their
version is used;
• Otherwise, the merge proceeds in the usual way.
renormalize
This runs a virtual check-out and check-in of all three
stages of a file when resolving a three-way merge. This
option is meant to be used when merging branches with
different clean filters or end-of-line normalization
rules. See "Merging branches with differing
checkin/checkout attributes" in gitattributes(5) for
details.
no-renormalize
Disables the renormalize option. This overrides the
merge.renormalize configuration variable.
find-renames[=<n>]
Turn on rename detection, optionally setting the
similarity threshold. This is the default. This overrides
the merge.renames configuration variable. See also
git-diff(1) --find-renames.
rename-threshold=<n>
Deprecated synonym for find-renames=<n>.
subtree[=<path>]
This option is a more advanced form of subtree strategy,
where the strategy makes a guess on how two trees must be
shifted to match with each other when merging. Instead,
the specified path is prefixed (or stripped from the
beginning) to make the shape of two trees to match.
recursive
This can only resolve two heads using a 3-way merge
algorithm. When there is more than one common ancestor that
can be used for 3-way merge, it creates a merged tree of the
common ancestors and uses that as the reference tree for the
3-way merge. This has been reported to result in fewer merge
conflicts without causing mismerges by tests done on actual
merge commits taken from Linux 2.6 kernel development
history. Additionally this can detect and handle merges
involving renames. It does not make use of detected copies.
This was the default strategy for resolving two heads from
Git v0.99.9k until v2.33.0.
The recursive strategy takes the same options as ort.
However, there are three additional options that ort ignores
(not documented above) that are potentially useful with the
recursive strategy:
patience
Deprecated synonym for diff-algorithm=patience.
diff-algorithm=[patience|minimal|histogram|myers]
Use a different diff algorithm while merging, which can
help avoid mismerges that occur due to unimportant
matching lines (such as braces from distinct functions).
See also git-diff(1) --diff-algorithm. Note that ort
specifically uses diff-algorithm=histogram, while
recursive defaults to the diff.algorithm config setting.
no-renames
Turn off rename detection. This overrides the
merge.renames configuration variable. See also
git-diff(1) --no-renames.
resolve
This can only resolve two heads (i.e. the current branch and
another branch you pulled from) using a 3-way merge
algorithm. It tries to carefully detect criss-cross merge
ambiguities. It does not handle renames.
octopus
This resolves cases with more than two heads, but refuses to
do a complex merge that needs manual resolution. It is
primarily meant to be used for bundling topic branch heads
together. This is the default merge strategy when pulling or
merging more than one branch.
ours
This resolves any number of heads, but the resulting tree of
the merge is always that of the current branch head,
effectively ignoring all changes from all other branches. It
is meant to be used to supersede old development history of
side branches. Note that this is different from the -Xours
option to the recursive merge strategy.
subtree
This is a modified ort strategy. When merging trees A and B,
if B corresponds to a subtree of A, B is first adjusted to
match the tree structure of A, instead of reading the trees
at the same level. This adjustment is also done to the common
ancestor tree.
With the strategies that use 3-way merge (including the default,
ort), if a change is made on both branches, but later reverted on
one of the branches, that change will be present in the merged
result; some people find this behavior confusing. It occurs
because only the heads and the merge base are considered when
performing a merge, not the individual commits. The merge
algorithm therefore considers the reverted change as no change at
all, and substitutes the changed version instead.
Often people use git pull without giving any parameter.
Traditionally, this has been equivalent to saying git pull
origin. However, when configuration branch.<name>.remote is
present while on branch <name>, that value is used instead of
origin.
In order to determine what URL to use to fetch from, the value of
the configuration remote.<origin>.url is consulted and if there
is not any such variable, the value on the URL: line in
$GIT_DIR/remotes/<origin> is used.
In order to determine what remote branches to fetch (and
optionally store in the remote-tracking branches) when the
command is run without any refspec parameters on the command
line, values of the configuration variable remote.<origin>.fetch
are consulted, and if there aren’t any, $GIT_DIR/remotes/<origin>
is consulted and its Pull: lines are used. In addition to the
refspec formats described in the OPTIONS section, you can have a
globbing refspec that looks like this:
refs/heads/*:refs/remotes/origin/*
A globbing refspec must have a non-empty RHS (i.e. must store
what were fetched in remote-tracking branches), and its LHS and
RHS must end with /*. The above specifies that all remote
branches are tracked using remote-tracking branches in
refs/remotes/origin/ hierarchy under the same name.
The rule to determine which remote branch to merge after fetching
is a bit involved, in order not to break backward compatibility.
If explicit refspecs were given on the command line of git pull,
they are all merged.
When no refspec was given on the command line, then git pull uses
the refspec from the configuration or $GIT_DIR/remotes/<origin>.
In such cases, the following rules apply:
1. If branch.<name>.merge configuration for the current branch
<name> exists, that is the name of the branch at the remote
site that is merged.
2. If the refspec is a globbing one, nothing is merged.
3. Otherwise the remote branch of the first refspec is merged.
• Update the remote-tracking branches for the repository you
cloned from, then merge one of them into your current branch:
$ git pull
$ git pull origin
Normally the branch merged in is the HEAD of the remote
repository, but the choice is determined by the
branch.<name>.remote and branch.<name>.merge options; see
git-config(1) for details.
• Merge into the current branch the remote branch next:
$ git pull origin next
This leaves a copy of next temporarily in FETCH_HEAD, and
updates the remote-tracking branch origin/next. The same can
be done by invoking fetch and merge:
$ git fetch origin
$ git merge origin/next
If you tried a pull which resulted in complex conflicts and would
want to start over, you can recover with git reset.
The fetch and push protocols are not designed to prevent one side
from stealing data from the other repository that was not
intended to be shared. If you have private data that you need to
protect from a malicious peer, your best option is to store it in
another repository. This applies to both clients and servers. In
particular, namespaces on a server are not effective for read
access control; you should only grant read access to a namespace
to clients that you would trust with read access to the entire
repository.
The known attack vectors are as follows:
1. The victim sends "have" lines advertising the IDs of objects
it has that are not explicitly intended to be shared but can
be used to optimize the transfer if the peer also has them.
The attacker chooses an object ID X to steal and sends a ref
to X, but isn’t required to send the content of X because the
victim already has it. Now the victim believes that the
attacker has X, and it sends the content of X back to the
attacker later. (This attack is most straightforward for a
client to perform on a server, by creating a ref to X in the
namespace the client has access to and then fetching it. The
most likely way for a server to perform it on a client is to
"merge" X into a public branch and hope that the user does
additional work on this branch and pushes it back to the
server without noticing the merge.)
2. As in #1, the attacker chooses an object ID X to steal. The
victim sends an object Y that the attacker already has, and
the attacker falsely claims to have X and not Y, so the
victim sends Y as a delta against X. The delta reveals
regions of X that are similar to Y to the attacker.
Using --recurse-submodules can only fetch new commits in already
checked out submodules right now. When e.g. upstream added a new
submodule in the just fetched commits of the superproject the
submodule itself cannot be fetched, making it impossible to check
out that submodule later without having to do a fetch again. This
is expected to be fixed in a future Git version.
git-fetch(1), git-merge(1), git-config(1)
Part of the git(1) suite
This page is part of the git (Git distributed version control
system) project. Information about the project can be found at
⟨http://git-scm.com/⟩. If you have a bug report for this manual
page, see ⟨http://git-scm.com/community⟩. This page was obtained
from the project's upstream Git repository
⟨https://github.com/git/git.git⟩ on 2024-06-14. (At that time,
the date of the most recent commit that was found in the
repository was 2024-06-12.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Git 2.45.2.492.gd63586 2024-06-12 GIT-PULL(1)
Pages that refer to this page: git(1), git-branch(1), git-config(1), git-fetch(1), git-merge(1), git-pull(1), git-push(1), stg(1), stg-repair(1), giteveryday(7), gitfaq(7), gitglossary(7), gittutorial(7), gitworkflows(7)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|