fast

GIT-PUSH(1)                                                                          Git Manual                                                                         GIT-PUSH(1)

NNAAMMEE
       git-push - Update remote refs along with associated objects

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

DDEESSCCRRIIPPTTIIOONN
       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 _h_o_o_k_s there. See documentation for ggiitt--rreecceeiivvee--ppaacckk(1).

       When the command line does not specify where to push with the <<rreeppoossiittoorryy>> argument, bbrraanncchh..**..rreemmoottee configuration for the current branch is consulted to determine where to
       push. If the configuration is missing, it defaults to _o_r_i_g_i_n.

       When the command line does not specify what to push with <<rreeffssppeecc>>...... arguments or ----aallll, ----mmiirrrroorr, ----ttaaggss options, the command finds the default <<rreeffssppeecc>> by consulting
       rreemmoottee..**..ppuusshh configuration, and if it is not found, honors ppuusshh..ddeeffaauulltt configuration to decide what to push (See ggiitt--ccoonnffiigg(1) for the meaning of ppuusshh..ddeeffaauulltt).

       When neither the command-line nor the configuration specify what to push, the default behavior is used, which corresponds to the ssiimmppllee value for ppuusshh..ddeeffaauulltt: 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.

OOPPTTIIOONNSS
       <repository>
           The "remote" repository that is 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 mmaasstteerr~~44 or HHEEAADD (see ggiittrreevviissiioonnss(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 ggiitt ppuusshh
           [[<<rreeppoossiittoorryy>>]] without any <<rreeffssppeecc>> argument is set to update some ref at the destination with <<ssrrcc>> with rreemmoottee..<<rreeppoossiittoorryy>>..ppuusshh configuration variable, ::<<ddsstt>> part
           can be omitted—such a push will update a ref that <<ssrrcc>> normally updates without any <<rreeffssppeecc>> on the command line. Otherwise, missing ::<<ddsstt>> means to update the same
           ref as the <<ssrrcc>>.

           If <dst> doesn’t start with rreeffss// (e.g.  rreeffss//hheeaaddss//mmaasstteerr) we will try to infer where in rreeffss//** 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
               aaddvviiccee..ppuusshhUUnnqquuaalliiffiieeddRReeffnnaammee configuration (see ggiitt--ccoonnffiigg(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 rreeffss//** 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 rreeffss//hheeaaddss//** namespace will only accept commit objects, and updates only if they can be fast-forwarded.

           The rreeffss//ttaaggss//** 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 rreeffss//{{ttaaggss,,hheeaaddss}}//**. In the case of tags and commits, these will be treated as if they were the
           commits inside rreeffss//hheeaaddss//** for the purposes of whether the update is allowed.

           I.e. a fast-forward of commits and tags outside rreeffss//{{ttaaggss,,hheeaaddss}}//** 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 rreeffss//{{ttaaggss,,hheeaaddss}}//** will be treated the same way as if they were inside rreeffss//ttaaggss//**, 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 ----ffoorrccee command line
           option). The only exception to this is that no amount of forcing will make the rreeffss//hheeaaddss//** namespace accept a non-commit object. Hooks and configuration can also
           override or amend these rules, see e.g.  rreecceeiivvee..ddeennyyNNoonnFFaassttFFoorrwwaarrddss in ggiitt--ccoonnffiigg(1) and pprree--rreecceeiivvee and uuppddaattee in ggiitthhooookkss(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 ----ffoorrccee),
           except when forbidden by configuration or hooks. See rreecceeiivvee..ddeennyyDDeelleetteess in ggiitt--ccoonnffiigg(1) and pprree--rreecceeiivvee and uuppddaattee in ggiitthhooookkss(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.

           ttaagg <<ttaagg>> means the same as rreeffss//ttaaggss//<<ttaagg>>::rreeffss//ttaaggss//<<ttaagg>>.

       --all
           Push all branches (i.e. refs under rreeffss//hheeaaddss//); cannot be used with other <refspec>.

       --prune
           Remove remote branches that don’t have a local counterpart. For example a remote branch ttmmpp will be removed if a local branch with the same name doesn’t exist any more.
           This also respects refspecs, e.g.  ggiitt ppuusshh ----pprruunnee rreemmoottee rreeffss//hheeaaddss//**::rreeffss//ttmmpp//** would make sure that remote rreeffss//ttmmpp//ffoooo will be removed if rreeffss//hheeaaddss//ffoooo doesn’t
           exist.

       --mirror
           Instead of naming each ref to push, specifies that all refs under rreeffss// (which includes but is not limited to rreeffss//hheeaaddss//, rreeffss//rreemmootteess//, and rreeffss//ttaaggss//) 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 rreemmoottee..<<rreemmoottee>>..mmiirrrroorr 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 rreeffss//ttaaggss 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 rreeffss//ttaaggss 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 ppuusshh..ffoolllloowwTTaaggss. For more information, see ppuusshh..ffoolllloowwTTaaggss in ggiitt--
           ccoonnffiigg(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 ffaallssee or ----nnoo--ssiiggnneedd, no signing will be
           attempted. If ttrruuee or ----ssiiggnneedd, the push will fail if the server does not support signed pushes. If set to iiff--aasskkeedd, sign if and only if the server supports signed
           pushes. The push will also fail if the actual call to ggppgg ----ssiiggnn fails. See ggiitt--rreecceeiivvee--ppaacckk(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 ----ppuusshh--ooppttiioonn==<<ooppttiioonn>> are given, they are all sent to the other side in the order listed on the command line. When no ----ppuusshh--ooppttiioonn==<<ooppttiioonn>> is given
           from the command line, the values of configuration variable ppuusshh..ppuusshhOOppttiioonn are used instead.

       --receive-pack=<git-receive-pack>, --exec=<git-receive-pack>
           Path to the _g_i_t_-_r_e_c_e_i_v_e_-_p_a_c_k 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
           her commit, and blindly pushing with ----ffoorrccee will lose her 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.

           ----ffoorrccee--wwiitthh--lleeaassee 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.

           ----ffoorrccee--wwiitthh--lleeaassee==<<rreeffnnaammee>>, 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.

           ----ffoorrccee--wwiitthh--lleeaassee==<<rreeffnnaammee>>::<<eexxppeecctt>> 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 <<eexxppeecctt>> (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 <<eexxppeecctt>> is the empty string, then the named ref must not already exist.

           Note that all forms other than ----ffoorrccee--wwiitthh--lleeaassee==<<rreeffnnaammee>>::<<eexxppeecctt>> 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 ----ffoorrccee--wwiitthh--lleeaassee or ----ffoorrccee--wwiitthh--lleeaassee==<<rreeffnnaammee>> interacts very badly with anything
           that implicitly runs ggiitt ffeettcchh on the remote to be pushed to in the background, e.g.  ggiitt ffeettcchh oorriiggiinn on your repository in a cronjob.

           The protection it offers over ----ffoorrccee 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 ggiitt ffeettcchh 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 ggiitt ffeettcchh oorriiggiinn the references on oorriiggiinn--ppuusshh won’t be updated, and thus commands like:

               git push --force-with-lease origin-push

           Will fail unless you manually run ggiitt ffeettcchh oorriiggiinn--ppuusshh. This method is of course entirely defeated by something that runs ggiitt ffeettcchh ----aallll, 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 bbaassee 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 mmaasstteerr
           if the remote version is still at bbaassee, regardless of what your local rreemmootteess//oorriiggiinn//mmaasstteerr has been updated to in the background.

       -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 ----ffoorrccee--wwiitthh--lleeaassee 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 ----ffoorrccee applies to all the refs that are pushed, hence using it with ppuusshh..ddeeffaauulltt set to mmaattcchhiinngg or with multiple push destinations configured with
           rreemmoottee..**..ppuusshh 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 ggiitt ppuusshh oorriiggiinn ++mmaasstteerr to force a push to the mmaasstteerr branch). See the <<rreeffssppeecc>>......  section above for details.

       --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 ggiitt--ppuullll(1) and other commands. For more
           information, see bbrraanncchh..<<nnaammee>>..mmeerrggee in ggiitt--ccoonnffiigg(1).

       --[no-]thin
           These options are passed to ggiitt--sseenndd--ppaacckk(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 ----tthhiinn.

       -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 _c_h_e_c_k 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 _o_n_-_d_e_m_a_n_d 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 _o_n_l_y is used all submodules will be recursively pushed while the superproject is left
           unpushed. A value of _n_o or using ----nnoo--rreeccuurrssee--ssuubbmmoodduulleess can be used to override the push.recurseSubmodules configuration variable when no submodule recursion is
           required.

       --[no-]verify
           Toggle the pre-push hook (see ggiitthhooookkss(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.

GGIITT UURRLLSS
       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
       ffoooo::bbaarr could be specified as an absolute path or ..//ffoooo::bbaarr 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 ggiitt--cclloonnee(1) for details.

       When Git doesn’t know how to handle a certain transport protocol, it attempts to use the _r_e_m_o_t_e_-_<_t_r_a_n_s_p_o_r_t_> 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 ggiittrreemmoottee--hheellppeerrss(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.

RREEMMOOTTEESS
       The name of one of the following can be used instead of a URL as <<rreeppoossiittoorryy>> argument:

       •   a remote in the Git configuration file: $$GGIITT__DDIIRR//ccoonnffiigg,

       •   a file in the $$GGIITT__DDIIRR//rreemmootteess directory, or

       •   a file in the $$GGIITT__DDIIRR//bbrraanncchheess 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.

   NNaammeedd rreemmoottee iinn ccoonnffiigguurraattiioonn ffiillee
       You can choose to provide the name of a remote which you had previously configured using ggiitt--rreemmoottee(1), ggiitt--ccoonnffiigg(1) or even by a manual edit to the $$GGIITT__DDIIRR//ccoonnffiigg 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 <<ppuusshhuurrll>> is used for pushes only. It is optional and defaults to <<uurrll>>.

   NNaammeedd ffiillee iinn $$GGIITT__DDIIRR//rreemmootteess
       You can choose to provide the name of a file in $$GGIITT__DDIIRR//rreemmootteess. 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>

       PPuusshh:: lines are used by _g_i_t _p_u_s_h and PPuullll:: lines are used by _g_i_t _p_u_l_l and _g_i_t _f_e_t_c_h. Multiple PPuusshh:: and PPuullll:: lines may be specified for additional branch mappings.

   NNaammeedd ffiillee iinn $$GGIITT__DDIIRR//bbrraanncchheess
       You can choose to provide the name of a file in $$GGIITT__DDIIRR//bbrraanncchheess. The URL in this file will be used to access the repository. This file should have the following format:

                   <url>#<head>

       <<uurrll>> is required; ##<<hheeaadd>> is optional.

       Depending on the operation, git will use one of the following refspecs, if you don’t provide one on the command line. <<bbrraanncchh>> is the name of this file in $$GGIITT__DDIIRR//bbrraanncchheess
       and <<hheeaadd>> defaults to mmaasstteerr.

       git fetch uses:

                   refs/heads/<head>:refs/heads/<branch>

       git push uses:

                   HEAD:refs/heads/<head>

OOUUTTPPUUTT
       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 ggiitt lloogg (this is <<oolldd>>....<<nneeww>> in most
           cases, and <<oolldd>>......<<nneeww>> 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:
               rreecceeiivvee..ddeennyyCCuurrrreennttBBrraanncchh (for pushes to the checked out branch), rreecceeiivvee..ddeennyyNNoonnFFaassttFFoorrwwaarrddss (for forced non-fast-forward updates), rreecceeiivvee..ddeennyyDDeelleetteess or
               rreecceeiivvee..ddeennyyDDeelleetteeCCuurrrreenntt. See ggiitt--ccoonnffiigg(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 rreeffss//<<ttyyppee>>// 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 rreeffss//<<ttyyppee>>// 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.

NNOOTTEE AABBOOUUTT FFAASSTT--FFOORRWWAARRDDSS
       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 _n_o_t 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.

EEXXAAMMPPLLEESS
       ggiitt ppuusshh
           Works like ggiitt ppuusshh <<rreemmoottee>>, where <remote> is the current branch’s remote (or oorriiggiinn, if no remote is configured for the current branch).

       ggiitt ppuusshh oorriiggiinn
           Without additional configuration, pushes the current branch to the configured upstream (rreemmoottee..oorriiggiinn..mmeerrggee 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 ppuusshh option of the remote, or the ppuusshh..ddeeffaauulltt configuration variable.

           For example, to default to pushing only the current branch to oorriiggiinn use ggiitt ccoonnffiigg rreemmoottee..oorriiggiinn..ppuusshh HHEEAADD. Any valid <refspec> (like the ones in the examples below)
           can be configured as the default for ggiitt ppuusshh oorriiggiinn.

       ggiitt ppuusshh oorriiggiinn ::
           Push "matching" branches to oorriiggiinn. See <refspec> in the OPTIONS section above for a description of "matching" branches.

       ggiitt ppuusshh oorriiggiinn mmaasstteerr
           Find a ref that matches mmaasstteerr in the source repository (most likely, it would find rreeffss//hheeaaddss//mmaasstteerr), and update the same ref (e.g.  rreeffss//hheeaaddss//mmaasstteerr) in oorriiggiinn
           repository with it. If mmaasstteerr did not exist remotely, it would be created.

       ggiitt ppuusshh oorriiggiinn HHEEAADD
           A handy way to push the current branch to the same name on the remote.

       ggiitt ppuusshh mmootthheerrsshhiipp mmaasstteerr::ssaatteelllliittee//mmaasstteerr ddeevv::ssaatteelllliittee//ddeevv
           Use the source ref that matches mmaasstteerr (e.g.  rreeffss//hheeaaddss//mmaasstteerr) to update the ref that matches ssaatteelllliittee//mmaasstteerr (most probably rreeffss//rreemmootteess//ssaatteelllliittee//mmaasstteerr) in the
           mmootthheerrsshhiipp repository; do the same for ddeevv and ssaatteelllliittee//ddeevv.

           See the section describing <<rreeffssppeecc>>......  above for a discussion of the matching semantics.

           This is to emulate ggiitt ffeettcchh run on the mmootthheerrsshhiipp using ggiitt ppuusshh that is run in the opposite direction in order to integrate the work done on ssaatteelllliittee, 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 ggiitt ppuusshh on the ssaatteelllliittee machine, you would ssh into the mmootthheerrsshhiipp and run ggiitt mmeerrggee there to complete the emulation of ggiitt ppuullll that were run on
           mmootthheerrsshhiipp to pull changes made on ssaatteelllliittee.

       ggiitt ppuusshh oorriiggiinn HHEEAADD::mmaasstteerr
           Push the current branch to the remote ref matching mmaasstteerr in the oorriiggiinn repository. This form is convenient to push the current branch without thinking about its local
           name.

       ggiitt ppuusshh oorriiggiinn mmaasstteerr::rreeffss//hheeaaddss//eexxppeerriimmeennttaall
           Create the branch eexxppeerriimmeennttaall in the oorriiggiinn repository by copying the current mmaasstteerr 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.

       ggiitt ppuusshh oorriiggiinn ::eexxppeerriimmeennttaall
           Find a ref that matches eexxppeerriimmeennttaall in the oorriiggiinn repository (e.g.  rreeffss//hheeaaddss//eexxppeerriimmeennttaall), and delete it.

       ggiitt ppuusshh oorriiggiinn ++ddeevv::mmaasstteerr
           Update the origin repository’s master branch with the dev branch, allowing non-fast-forward updates.  TThhiiss ccaann lleeaavvee uunnrreeffeerreenncceedd ccoommmmiittss ddaanngglliinngg iinn tthhee oorriiggiinn
           rreeppoossiittoorryy..  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 ggiitt ggcc command on the
           origin repository.

SSEECCUURRIITTYY
       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.

GGIITT
       Part of the ggiitt(1) suite

Git 2.23.0                                                                           08/16/2019                                                                         GIT-PUSH(1)