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.
--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
http://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 special 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.
--all
Fetch all remotes.
-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 accept 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.
-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’s
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 the optional leading + to a refspec (or using
--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 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 it).
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.xz[:port]/path/to/repo.git/
•git://host.xz[:port]/path/to/repo.git/
•http[s]://host.xz[:port]/path/to/repo.git/
•ftp[s]://host.xz[:port]/path/to/repo.git/
An alternative scp-like syntax may also be used with the ssh
protocol:
•[user@]host.xz:path/to/repo.git/
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.xz[:port]/~[user]/path/to/repo.git/
•git://host.xz[:port]/~[user]/path/to/repo.git/
•[user@]host.xz:/~[user]/path/to/repo.git/
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.
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>.
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 format
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> 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:
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:
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.