# git-push

## NAME



           git-push - Update remote refs along with associated objects
    


## SYNOPSIS



           _git push_ [--all | --branches | --mirror | --tags] [--follow-tags] [--atomic] [-n | --dry-run] [--receive-pack=<git-receive-pack>]
                      [--repo=<repository>] [-f | --force] [-d | --delete] [--prune] [-q | --quiet] [-v | --verbose]
                      [-u | --set-upstream] [-o <string> | --push-option=<string>]
                      [--[no-]signed|--signed=(true|false|if-asked)]
                      [--force-with-lease[=<refname>[:<expect>]] [--force-if-includes]]
                      [--no-verify] [<repository> [<refspec>...]]
    


## DESCRIPTION



           Updates remote refs using local refs, while sending objects
           necessary to complete the given refs.
    
           You can make interesting things happen to a repository every time
           you push into it, by setting up _hooks_ there. See documentation for
           git-receive-pack(1).
    
           When the command line does not specify where to push with the
           _< repository>_ argument, **branch.*.remote** configuration for the
           current branch is consulted to determine where to push. If the
           configuration is missing, it defaults to _origin_.
    
           When the command line does not specify what to push with
           _< refspec>_... arguments or **--all** , **--mirror** , **--tags** options, the
           command finds the default _< refspec>_ by consulting **remote.*.push**
           configuration, and if it is not found, honors **push.default**
           configuration to decide what to push (See git-config(1) for the
           meaning of **push.default**).
    
           When neither the command-line nor the configuration specifies what
           to push, the default behavior is used, which corresponds to the
           **simple** value for **push.default** : the current branch is pushed to the
           corresponding upstream branch, but as a safety measure, the push
           is aborted if the upstream branch does not have the same name as
           the local one.
    


## OPTIONS



           <repository>
               The "remote" repository that is the destination of a push
               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>...
               Specify what destination ref to update with what source
               object. The format of a <refspec> parameter is an optional
               plus **+** , followed by the source object <src>, followed by a
               colon **:** , followed by the destination ref <dst>.
    
               The <src> is often the name of the branch you would want to
               push, but it can be any arbitrary "SHA-1 expression", such as
               **master~4** or **HEAD**(see gitrevisions(7)).
    
               The <dst> tells which ref on the remote side is updated with
               this push. Arbitrary expressions cannot be used here, an
               actual ref must be named. If **git push**[_< repository>_] without
               any _< refspec>_ argument is set to update some ref at the
               destination with _< src>_ with **remote.**_< repository>_**.push**
               configuration variable, **:**_< dst>_ part can be omitted—such a push
               will update a ref that _< src>_ normally updates without any
               _< refspec>_ on the command line. Otherwise, missing **:**_< dst>_ means
               to update the same ref as the _< src>_.
    
               If <dst> doesn’t start with **refs/**(e.g.  **refs/heads/master**) we
               will try to infer where in **refs/*** on the destination
               <repository> it belongs based on the type of <src> being
               pushed and whether <dst> is ambiguous.
    
               •   If <dst> unambiguously refers to a ref on the <repository>
                   remote, then push to that ref.
    
               •   If <src> resolves to a ref starting with refs/heads/ or
                   refs/tags/, then prepend that to <dst>.
    
               •   Other ambiguity resolutions might be added in the future,
                   but for now any other cases will error out with an error
                   indicating what we tried, and depending on the
                   **advice.pushUnqualifiedRefname** configuration (see
                   git-config(1)) suggest what refs/ namespace you may have
                   wanted to push to.
    
               The object referenced by <src> is used to update the <dst>
               reference on the remote side. Whether this is allowed depends
               on where in **refs/*** the <dst> reference lives as described in
               detail below, in those sections "update" means any
               modifications except deletes, which as noted after the next
               few sections are treated differently.
    
               The **refs/heads/*** namespace will only accept commit objects,
               and updates only if they can be fast-forwarded.
    
               The **refs/tags/*** namespace will accept any kind of object (as
               commits, trees and blobs can be tagged), and any updates to
               them will be rejected.
    
               It’s possible to push any type of object to any namespace
               outside of **refs/**{tags,heads}/*. In the case of tags and
               commits, these will be treated as if they were the commits
               inside **refs/heads/*** for the purposes of whether the update is
               allowed.
    
               I.e. a fast-forward of commits and tags outside
               **refs/**{tags,heads}/* is allowed, even in cases where what’s
               being fast-forwarded is not a commit, but a tag object which
               happens to point to a new commit which is a fast-forward of
               the commit the last tag (or commit) it’s replacing. Replacing
               a tag with an entirely different tag is also allowed, if it
               points to the same commit, as well as pushing a peeled tag,
               i.e. pushing the commit that existing tag object points to, or
               a new tag object which an existing commit points to.
    
               Tree and blob objects outside of **refs/**{tags,heads}/* will be
               treated the same way as if they were inside **refs/tags/*** , any
               update of them will be rejected.
    
               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. Hooks
               and configuration can also override or amend these rules, see
               e.g.  **receive.denyNonFastForwards** in git-config(1) and
               **pre-receive** and **update** in githooks(5).
    
               Pushing an empty <src> allows you to delete the <dst> ref from
               the remote repository. Deletions are always accepted without a
               leading **+** in the refspec (or **--force**), except when forbidden
               by configuration or hooks. See **receive.denyDeletes** in
               git-config(1) and **pre-receive** and **update** in githooks(5).
    
               The special refspec **:**(or **+:** to allow non-fast-forward
               updates) directs Git to push "matching" branches: for every
               branch that exists on the local side, the remote side is
               updated if a branch of the same name already exists on the
               remote side.
    
               **tag** _< tag>_ means the same as **refs/tags/**_< tag>_**:refs/tags/**_< tag>_.
    
           --all, --branches
               Push all branches (i.e. refs under **refs/heads/**); cannot be
               used with other <refspec>.
    
           --prune
               Remove remote branches that don’t have a local counterpart.
               For example a remote branch **tmp** will be removed if a local
               branch with the same name doesn’t exist any more. This also
               respects refspecs, e.g.  **git push --prune remote**
               **refs/heads/*:refs/tmp/*** would make sure that remote
               **refs/tmp/foo** will be removed if **refs/heads/foo** doesn’t exist.
    
           --mirror
               Instead of naming each ref to push, specifies that all refs
               under **refs/**(which includes but is not limited to **refs/heads/** ,
               **refs/remotes/** , and **refs/tags/**) be mirrored to the remote
               repository. Newly created local refs will be pushed to the
               remote end, locally updated refs will be force updated on the
               remote end, and deleted refs will be removed from the remote
               end. This is the default if the configuration option
               **remote.**_< remote>_**.mirror** is set.
    
           -n, --dry-run
               Do everything except actually send the updates.
    
           --porcelain
               Produce machine-readable output. The output status line for
               each ref will be tab-separated and sent to stdout instead of
               stderr. The full symbolic names of the refs will be given.
    
           -d, --delete
               All listed refs are deleted from the remote repository. This
               is the same as prefixing all refs with a colon.
    
           --tags
               All refs under **refs/tags** are pushed, in addition to refspecs
               explicitly listed on the command line.
    
           --follow-tags
               Push all the refs that would be pushed without this option,
               and also push annotated tags in **refs/tags** that are missing
               from the remote but are pointing at commit-ish that are
               reachable from the refs being pushed. This can also be
               specified with configuration variable **push.followTags**. For
               more information, see **push.followTags** in git-config(1).
    
           --[no-]signed, --signed=(true|false|if-asked)
               GPG-sign the push request to update refs on the receiving
               side, to allow it to be checked by the hooks and/or be logged.
               If **false** or **--no-signed** , no signing will be attempted. If **true**
               or **--signed** , the push will fail if the server does not support
               signed pushes. If set to **if-asked** , sign if and only if the
               server supports signed pushes. The push will also fail if the
               actual call to **gpg --sign** fails. See git-receive-pack(1) for
               the details on the receiving end.
    
           --[no-]atomic
               Use an atomic transaction on the remote side if available.
               Either all refs are updated, or on error, no refs are updated.
               If the server does not support atomic pushes the push will
               fail.
    
           -o <option>, --push-option=<option>
               Transmit the given string to the server, which passes them to
               the pre-receive as well as the post-receive hook. The given
               string must not contain a NUL or LF character. When multiple
               **--push-option=**_< option>_ are given, they are all sent to the
               other side in the order listed on the command line. When no
               **--push-option=**_< option>_ is given from the command line, the
               values of configuration variable **push.pushOption** are used
               instead.
    
           --receive-pack=<git-receive-pack>, --exec=<git-receive-pack>
               Path to the _git-receive-pack_ program on the remote end.
               Sometimes useful when pushing to a remote repository over ssh,
               and you do not have the program in a directory on the default
               $PATH.
    
           --[no-]force-with-lease, --force-with-lease=<refname>,
           --force-with-lease=<refname>:<expect>
               Usually, "git push" refuses to update a remote ref that is not
               an ancestor of the local ref used to overwrite it.
    
               This option overrides this restriction if the current value of
               the remote ref is the expected value. "git push" fails
               otherwise.
    
               Imagine that you have to rebase what you have already
               published. You will have to bypass the "must fast-forward"
               rule in order to replace the history you originally published
               with the rebased history. If somebody else built on top of
               your original history while you are rebasing, the tip of the
               branch at the remote may advance with their commit, and
               blindly pushing with **--force** will lose their work.
    
               This option allows you to say that you expect the history you
               are updating is what you rebased and want to replace. If the
               remote ref still points at the commit you specified, you can
               be sure that no other people did anything to the ref. It is
               like taking a "lease" on the ref without explicitly locking
               it, and the remote ref is updated only if the "lease" is still
               valid.
    
               **--force-with-lease** alone, without specifying the details, will
               protect all remote refs that are going to be updated by
               requiring their current value to be the same as the
               remote-tracking branch we have for them.
    
               **--force-with-lease=**_< refname>_, without specifying the expected
               value, will protect the named ref (alone), if it is going to
               be updated, by requiring its current value to be the same as
               the remote-tracking branch we have for it.
    
               **--force-with-lease=**_< refname>_**:**_< expect>_ will protect the named
               ref (alone), if it is going to be updated, by requiring its
               current value to be the same as the specified value _< expect>_
               (which is allowed to be different from the remote-tracking
               branch we have for the refname, or we do not even have to have
               such a remote-tracking branch when this form is used). If
               _< expect>_ is the empty string, then the named ref must not
               already exist.
    
               Note that all forms other than
               **--force-with-lease=**_< refname>_**:**_< expect>_ that specifies the
               expected current value of the ref explicitly are still
               experimental and their semantics may change as we gain
               experience with this feature.
    
               "--no-force-with-lease" will cancel all the previous
               --force-with-lease on the command line.
    
               A general note on safety: supplying this option without an
               expected value, i.e. as **--force-with-lease** or
               **--force-with-lease=**_< refname>_ interacts very badly with
               anything that implicitly runs **git fetch** on the remote to be
               pushed to in the background, e.g.  **git fetch origin** on your
               repository in a cronjob.
    
               The protection it offers over **--force** is ensuring that
               subsequent changes your work wasn’t based on aren’t clobbered,
               but this is trivially defeated if some background process is
               updating refs in the background. We don’t have anything except
               the remote tracking info to go by as a heuristic for refs
               you’re expected to have seen & are willing to clobber.
    
               If your editor or some other system is running **git fetch** in
               the background for you a way to mitigate this is to simply set
               up another remote:
    
                   git remote add origin-push $(git config remote.origin.url)
                   git fetch origin-push
    
               Now when the background process runs **git fetch origin** the
               references on **origin-push** won’t be updated, and thus commands
               like:
    
                   git push --force-with-lease origin-push
    
               Will fail unless you manually run **git fetch origin-push**. This
               method is of course entirely defeated by something that runs
               **git fetch --all** , in that case you’d need to either disable it
               or do something more tedious like:
    
                   git fetch              # update 'master' from remote
                   git tag base master    # mark our base point
                   git rebase -i master   # rewrite some commits
                   git push --force-with-lease=master:base master:master
    
               I.e. create a **base** tag for versions of the upstream code that
               you’ve seen and are willing to overwrite, then rewrite
               history, and finally force push changes to **master** if the
               remote version is still at **base** , regardless of what your local
               **remotes/origin/master** has been updated to in the background.
    
               Alternatively, specifying **--force-if-includes** as an ancillary
               option along with **--force-with-lease**[**=**_< refname>_] (i.e.,
               without saying what exact commit the ref on the remote side
               must be pointing at, or which refs on the remote side are
               being protected) at the time of "push" will verify if updates
               from the remote-tracking refs that may have been implicitly
               updated in the background are integrated locally before
               allowing a forced update.
    
           -f, --force
               Usually, the command refuses to update a remote ref that is
               not an ancestor of the local ref used to overwrite it. Also,
               when **--force-with-lease** option is used, the command refuses to
               update a remote ref whose current value does not match what is
               expected.
    
               This flag disables these checks, and can cause the remote
               repository to lose commits; use it with care.
    
               Note that **--force** applies to all the refs that are pushed,
               hence using it with **push.default** set to **matching** or with
               multiple push destinations configured with **remote.*.push** may
               overwrite refs other than the current branch (including local
               refs that are strictly behind their remote counterpart). To
               force a push to only one branch, use a **+** in front of the
               refspec to push (e.g **git push origin +master** to force a push
               to the **master** branch). See the _< refspec>_... section above for
               details.
    
           --[no-]force-if-includes
               Force an update only if the tip of the remote-tracking ref has
               been integrated locally.
    
               This option enables a check that verifies if the tip of the
               remote-tracking ref is reachable from one of the "reflog"
               entries of the local branch based in it for a rewrite. The
               check ensures that any updates from the remote have been
               incorporated locally by rejecting the forced update if that is
               not the case.
    
               If the option is passed without specifying **--force-with-lease** ,
               or specified along with **--force-with-lease=**_< refname>_**:**_< expect>_,
               it is a "no-op".
    
               Specifying **--no-force-if-includes** disables this behavior.
    
           --repo=<repository>
               This option is equivalent to the <repository> argument. If
               both are specified, the command-line argument takes
               precedence.
    
           -u, --set-upstream
               For every branch that is up to date or successfully pushed,
               add upstream (tracking) reference, used by argument-less
               git-pull(1) and other commands. For more information, see
               **branch.**_< name>_**.merge** in git-config(1).
    
           --[no-]thin
               These options are passed to git-send-pack(1). A thin transfer
               significantly reduces the amount of sent data when the sender
               and receiver share many of the same objects in common. The
               default is **--thin**.
    
           -q, --quiet
               Suppress all output, including the listing of updated refs,
               unless an error occurs. Progress is not reported to the
               standard error stream.
    
           -v, --verbose
               Run verbosely.
    
           --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.
    
           --no-recurse-submodules,
           --recurse-submodules=check|on-demand|only|no
               May be used to make sure all submodule commits used by the
               revisions to be pushed are available on a remote-tracking
               branch. If _check_ is used Git will verify that all submodule
               commits that changed in the revisions to be pushed are
               available on at least one remote of the submodule. If any
               commits are missing the push will be aborted and exit with
               non-zero status. If _on-demand_ is used all submodules that
               changed in the revisions to be pushed will be pushed. If
               on-demand was not able to push all necessary revisions it will
               also be aborted and exit with non-zero status. If _only_ is used
               all submodules will be pushed while the superproject is left
               unpushed. A value of _no_ or using **--no-recurse-submodules** can
               be used to override the push.recurseSubmodules configuration
               variable when no submodule recursion is required.
    
               When using _on-demand_ or _only_ , if a submodule has a
               "push.recurseSubmodules={on-demand,only}" or
               "submodule.recurse" configuration, further recursion will
               occur. In this case, "only" is treated as "on-demand".
    
           --[no-]verify
               Toggle the pre-push hook (see githooks(5)). The default is
               --verify, giving the hook a chance to prevent the push. With
               --no-verify, the hook is bypassed completely.
    
           -4, --ipv4
               Use IPv4 addresses only, ignoring IPv6 addresses.
    
           -6, --ipv6
               Use IPv6 addresses only, ignoring IPv4 addresses.
    


## GIT URLS



           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.
    


## REMOTES



           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>
    


## OUTPUT



           The output of "git push" depends on the transport method used;
           this section describes the output when pushing over the Git
           protocol (either locally or via ssh).
    
           The status of the push is output in tabular form, with each line
           representing the status of a single ref. Each line is of the form:
    
                <flag> <summary> <from> -> <to> (<reason>)
    
           If --porcelain is used, then each line of the output is of the
           form:
    
                <flag> \t <from>:<to> \t <summary> (<reason>)
    
           The status of up-to-date refs is shown only if --porcelain or
           --verbose option is used.
    
           flag
               A single character indicating the status of the ref:
    
               (space)
                   for a successfully pushed fast-forward;
    
               **+**
                   for a successful forced update;
    
               **-**
                   for a successfully deleted ref;
    
               *****
                   for a successfully pushed new ref;
    
               !
                   for a ref that was rejected or failed to push; and
    
               **=**
                   for a ref that was up to date and did not need pushing.
    
           summary
               For a successfully pushed ref, the summary shows the old and
               new values of the ref in a form suitable for using as an
               argument to **git log**(this is _< old>_**..**_< new>_ in most cases, and
               _< old>_**...**_< new>_ for forced non-fast-forward updates).
    
               For a failed update, more details are given:
    
               rejected
                   Git did not try to send the ref at all, typically because
                   it is not a fast-forward and you did not force the update.
    
               remote rejected
                   The remote end refused the update. Usually caused by a
                   hook on the remote side, or because the remote repository
                   has one of the following safety options in effect:
                   **receive.denyCurrentBranch**(for pushes to the checked out
                   branch), **receive.denyNonFastForwards**(for forced
                   non-fast-forward updates), **receive.denyDeletes** or
                   **receive.denyDeleteCurrent**. See git-config(1).
    
               remote failure
                   The remote end did not report the successful update of the
                   ref, perhaps because of a temporary error on the remote
                   side, a break in the network connection, or other
                   transient error.
    
           from
               The name of the local ref being pushed, minus its **refs/**_< type>_**/**
               prefix. In the case of deletion, the name of the local ref is
               omitted.
    
           to
               The name of the remote ref being updated, minus its
               **refs/**_< type>_**/** prefix.
    
           reason
               A human-readable explanation. In the case of successfully
               pushed refs, no explanation is needed. For a failed ref, the
               reason for failure is described.
    


## NOTE ABOUT FAST-FORWARDS



           When an update changes a branch (or more in general, a ref) that
           used to point at commit A to point at another commit B, it is
           called a fast-forward update if and only if B is a descendant of
           A.
    
           In a fast-forward update from A to B, the set of commits that the
           original commit A built on top of is a subset of the commits the
           new commit B builds on top of. Hence, it does not lose any
           history.
    
           In contrast, a non-fast-forward update will lose history. For
           example, suppose you and somebody else started at the same commit
           X, and you built a history leading to commit B while the other
           person built a history leading to commit A. The history looks like
           this:
    
                     B
                    /
                ---X---A
    
           Further suppose that the other person already pushed changes
           leading to A back to the original repository from which you two
           obtained the original commit X.
    
           The push done by the other person updated the branch that used to
           point at commit X to point at commit A. It is a fast-forward.
    
           But if you try to push, you will attempt to update the branch
           (that now points at A) with commit B. This does _not_ fast-forward.
           If you did so, the changes introduced by commit A will be lost,
           because everybody will now start building on top of B.
    
           The command by default does not allow an update that is not a
           fast-forward to prevent such loss of history.
    
           If you do not want to lose your work (history from X to B) or the
           work by the other person (history from X to A), you would need to
           first fetch the history from the repository, create a history that
           contains changes done by both parties, and push the result back.
    
           You can perform "git pull", resolve potential conflicts, and "git
           push" the result. A "git pull" will create a merge commit C
           between commits A and B.
    
                     B---C
                    /   /
                ---X---A
    
           Updating A with the resulting merge commit will fast-forward and
           your push will be accepted.
    
           Alternatively, you can rebase your change between X and B on top
           of A, with "git pull --rebase", and push the result back. The
           rebase will create a new commit D that builds the change between X
           and B on top of A.
    
                     B   D
                    /   /
                ---X---A
    
           Again, updating A with this commit will fast-forward and your push
           will be accepted.
    
           There is another common situation where you may encounter
           non-fast-forward rejection when you try to push, and it is
           possible even when you are pushing into a repository nobody else
           pushes into. After you push commit A yourself (in the first
           picture in this section), replace it with "git commit --amend" to
           produce commit B, and you try to push it out, because forgot that
           you have pushed A out already. In such a case, and only if you are
           certain that nobody in the meantime fetched your earlier commit A
           (and started building on top of it), you can run "git push
           --force" to overwrite it. In other words, "git push --force" is a
           method reserved for a case where you do mean to lose history.
    


## EXAMPLES



           **git push**
               Works like **git push** _< remote>_, where <remote> is the current
               branch’s remote (or **origin** , if no remote is configured for the
               current branch).
    
           **git push origin**
               Without additional configuration, pushes the current branch to
               the configured upstream (**branch.**_< name>_**.merge** configuration
               variable) if it has the same name as the current branch, and
               errors out without pushing otherwise.
    
               The default behavior of this command when no <refspec> is
               given can be configured by setting the **push** option of the
               remote, or the **push.default** configuration variable.
    
               For example, to default to pushing only the current branch to
               **origin** use **git config remote.origin.push HEAD**. Any valid
               <refspec> (like the ones in the examples below) can be
               configured as the default for **git push origin**.
    
           **git push origin :**
               Push "matching" branches to **origin**. See <refspec> in the
               OPTIONS section above for a description of "matching"
               branches.
    
           **git push origin master**
               Find a ref that matches **master** in the source repository (most
               likely, it would find **refs/heads/master**), and update the same
               ref (e.g.  **refs/heads/master**) in **origin** repository with it. If
               **master** did not exist remotely, it would be created.
    
           **git push origin HEAD**
               A handy way to push the current branch to the same name on the
               remote.
    
           **git push mothership master:satellite/master dev:satellite/dev**
               Use the source ref that matches **master**(e.g.
               **refs/heads/master**) to update the ref that matches
               **satellite/master**(most probably **refs/remotes/satellite/master**)
               in the **mothership** repository; do the same for **dev** and
               **satellite/dev**.
    
               See the section describing _< refspec>_... above for a discussion
               of the matching semantics.
    
               This is to emulate **git fetch** run on the **mothership** using **git**
               **push** that is run in the opposite direction in order to
               integrate the work done on **satellite** , and is often necessary
               when you can only make connection in one way (i.e. satellite
               can ssh into mothership but mothership cannot initiate
               connection to satellite because the latter is behind a
               firewall or does not run sshd).
    
               After running this **git push** on the **satellite** machine, you
               would ssh into the **mothership** and run **git merge** there to
               complete the emulation of **git pull** that were run on **mothership**
               to pull changes made on **satellite**.
    
           **git push origin HEAD:master**
               Push the current branch to the remote ref matching **master** in
               the **origin** repository. This form is convenient to push the
               current branch without thinking about its local name.
    
           **git push origin master:refs/heads/experimental**
               Create the branch **experimental** in the **origin** repository by
               copying the current **master** branch. This form is only needed to
               create a new branch or tag in the remote repository when the
               local name and the remote name are different; otherwise, the
               ref name on its own will work.
    
           **git push origin :experimental**
               Find a ref that matches **experimental** in the **origin** repository
               (e.g.  **refs/heads/experimental**), and delete it.
    
           **git push origin +dev:master**
               Update the origin repository’s master branch with the dev
               branch, allowing non-fast-forward updates.  **This can leave**
               **unreferenced commits dangling in the origin repository.**
               Consider the following situation, where a fast-forward is not
               possible:
    
                               o---o---o---A---B  origin/master
                                        \
                                         X---Y---Z  dev
    
               The above command would change the origin repository to
    
                                         A---B  (unnamed branch)
                                        /
                               o---o---o---X---Y---Z  master
    
               Commits A and B would no longer belong to a branch with a
               symbolic name, and so would be unreachable. As such, these
               commits would be removed by a **git gc** command on the origin
               repository.
    


## SECURITY



           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.
    


## CONFIGURATION



           Everything below this line in this section is selectively included
           from the git-config(1) documentation. The content is the same as
           what’s found there:
    
           push.autoSetupRemote
               If set to "true" assume **--set-upstream** on default push when no
               upstream tracking exists for the current branch; this option
               takes effect with push.default options _simple_ , _upstream_ , and
               _current_. It is useful if by default you want new branches to
               be pushed to the default remote (like the behavior of
               _push.default=current_) and you also want the upstream tracking
               to be set. Workflows most likely to benefit from this option
               are _simple_ central workflows where all branches are expected
               to have the same name on the remote.
    
           push.default
               Defines the action **git push** should take if no refspec is given
               (whether from the command-line, config, or elsewhere).
               Different values are well-suited for specific workflows; for
               instance, in a purely central workflow (i.e. the fetch source
               is equal to the push destination), **upstream** is probably what
               you want. Possible values are:
    
               •   **nothing** - do not push anything (error out) unless a
                   refspec is given. This is primarily meant for people who
                   want to avoid mistakes by always being explicit.
    
               •   **current** - push the current branch to update a branch with
                   the same name on the receiving end. Works in both central
                   and non-central workflows.
    
               •   **upstream** - push the current branch back to the branch
                   whose changes are usually integrated into the current
                   branch (which is called **@**{upstream}). This mode only makes
                   sense if you are pushing to the same repository you would
                   normally pull from (i.e. central workflow).
    
               •   **tracking** - This is a deprecated synonym for **upstream**.
    
               •   **simple** - push the current branch with the same name on the
                   remote.
    
                   If you are working on a centralized workflow (pushing to
                   the same repository you pull from, which is typically
                   **origin**), then you need to configure an upstream branch
                   with the same name.
    
                   This mode is the default since Git 2.0, and is the safest
                   option suited for beginners.
    
               •   **matching** - push all branches having the same name on both
                   ends. This makes the repository you are pushing to
                   remember the set of branches that will be pushed out (e.g.
                   if you always push _maint_ and _master_ there and no other
                   branches, the repository you push to will have these two
                   branches, and your local _maint_ and _master_ will be pushed
                   there).
    
                   To use this mode effectively, you have to make sure _all_
                   the branches you would push out are ready to be pushed out
                   before running _git push_ , as the whole point of this mode
                   is to allow you to push all of the branches in one go. If
                   you usually finish work on only one branch and push out
                   the result, while other branches are unfinished, this mode
                   is not for you. Also this mode is not suitable for pushing
                   into a shared central repository, as other people may add
                   new branches there, or update the tip of existing branches
                   outside your control.
    
                   This used to be the default, but not since Git 2.0 (**simple**
                   is the new default).
    
           push.followTags
               If set to true, enable **--follow-tags** option by default. You
               may override this configuration at time of push by specifying
               **--no-follow-tags**.
    
           push.gpgSign
               May be set to a boolean value, or the string _if-asked_. A true
               value causes all pushes to be GPG signed, as if **--signed** is
               passed to git-push(1). The string _if-asked_ causes pushes to be
               signed if the server supports it, as if **--signed=if-asked** is
               passed to _git push_. A false value may override a value from a
               lower-priority config file. An explicit command-line flag
               always overrides this config option.
    
           push.pushOption
               When no **--push-option=**_< option>_ argument is given from the
               command line, **git push** behaves as if each <value> of this
               variable is given as **--push-option=**_< value>_.
    
               This is a multi-valued variable, and an empty value can be
               used in a higher priority configuration file (e.g.
               **.git/config** in a repository) to clear the values inherited
               from a lower priority configuration files (e.g.
               **$HOME/.gitconfig**).
    
                   Example:
    
                   /etc/gitconfig
                     push.pushoption = a
                     push.pushoption = b
    
                   ~/.gitconfig
                     push.pushoption = c
    
                   repo/.git/config
                     push.pushoption =
                     push.pushoption = b
    
                   This will result in only b (a and c are cleared).
    
           push.recurseSubmodules
               May be "check", "on-demand", "only", or "no", with the same
               behavior as that of "push --recurse-submodules". If not set,
               _no_ is used by default, unless _submodule.recurse_ is set (in
               which case a _true_ value means _on-demand_).
    
           push.useForceIfIncludes
               If set to "true", it is equivalent to specifying
               **--force-if-includes** as an option to git-push(1) in the command
               line. Adding **--no-force-if-includes** at the time of push
               overrides this configuration setting.
    
           push.negotiate
               If set to "true", attempt to reduce the size of the packfile
               sent by rounds of negotiation in which the client and the
               server attempt to find commits in common. If "false", Git will
               rely solely on the server’s ref advertisement to find commits
               in common.
    
           push.useBitmaps
               If set to "false", disable use of bitmaps for "git push" even
               if **pack.useBitmaps** is "true", without preventing other git
               operations from using bitmaps. Default is true.
    


## GIT



           Part of the git(1) suite
    


* * *