fetch: opportunistically update tracking refs
[git/git.git] / Documentation / pull-fetch-param.txt
... / ...
CommitLineData
1<repository>::
2 The "remote" repository that is the source of a fetch
3 or pull operation. This parameter can be either a URL
4 (see the section <<URLS,GIT URLS>> below) or the name
5 of a remote (see the section <<REMOTES,REMOTES>> below).
6
7ifndef::git-pull[]
8<group>::
9 A name referring to a list of repositories as the value
10 of remotes.<group> in the configuration file.
11 (See linkgit:git-config[1]).
12endif::git-pull[]
13
14<refspec>::
15 The format of a <refspec> parameter is an optional plus
16 `+`, followed by the source ref <src>, followed
17 by a colon `:`, followed by the destination ref <dst>.
18+
19The remote ref that matches <src>
20is fetched, and if <dst> is not empty string, the local
21ref that matches it is fast-forwarded using <src>.
22If the optional plus `+` is used, the local ref
23is updated even if it does not result in a fast-forward
24update.
25+
26[NOTE]
27If the remote branch from which you want to pull is
28modified in non-linear ways such as being rewound and
29rebased frequently, then a pull will attempt a merge with
30an older version of itself, likely conflict, and fail.
31It is under these conditions that you would want to use
32the `+` sign to indicate non-fast-forward updates will
33be needed. There is currently no easy way to determine
34or declare that a branch will be made available in a
35repository with this behavior; the pulling user simply
36must know this is the expected usage pattern for a branch.
37+
38[NOTE]
39You never do your own development on branches that appear
40on the right hand side of a <refspec> colon on `Pull:` lines;
41they are to be updated by 'git fetch'. If you intend to do
42development derived from a remote branch `B`, have a `Pull:`
43line to track it (i.e. `Pull: B:remote-B`), and have a separate
44branch `my-B` to do your development on top of it. The latter
45is created by `git branch my-B remote-B` (or its equivalent `git
46checkout -b my-B remote-B`). Run `git fetch` to keep track of
47the progress of the remote side, and when you see something new
48on the remote branch, merge it into your development branch with
49`git pull . remote-B`, while you are on `my-B` branch.
50+
51[NOTE]
52There is a difference between listing multiple <refspec>
53directly on 'git pull' command line and having multiple
54`Pull:` <refspec> lines for a <repository> and running
55'git pull' command without any explicit <refspec> parameters.
56<refspec> listed explicitly on the command line are always
57merged into the current branch after fetching. In other words,
58if you list more than one remote refs, you would be making
59an Octopus. While 'git pull' run without any explicit <refspec>
60parameter takes default <refspec>s from `Pull:` lines, it
61merges only the first <refspec> found into the current branch,
62after fetching all the remote refs. This is because making an
63Octopus from remote refs is rarely done, while keeping track
64of multiple remote heads in one-go by fetching more than one
65is often useful.
66+
67Some short-cut notations are also supported.
68+
69* `tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`;
70 it requests fetching everything up to the given tag.
71ifndef::git-pull[]
72* A parameter <ref> without a colon fetches that ref into FETCH_HEAD,
73endif::git-pull[]
74ifdef::git-pull[]
75* A parameter <ref> without a colon merges <ref> into the current
76 branch,
77endif::git-pull[]
78 and updates the remote-tracking branches (if any).