Documentation/pull-fetch-param.txt

   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
   7 ifndef::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]).
  12 endif::git-pull[]
  13
  14 <refspec>::
  15         Specifies which refs to fetch and which local refs to update.
  16         When no <refspec>s appear on the command line, the refs to fetch
  17         are read from `remote.<repository>.fetch` variables instead
  18 ifndef::git-pull[]
  19         (see <<CRTB,CONFIGURED REMOTE-TRACKING BRANCHES>> below).
  20 endif::git-pull[]
  21 ifdef::git-pull[]
  22         (see linkgit:git-fetch[1]).
  23 endif::git-pull[]
  24 +
  25 The format of a <refspec> parameter is an optional plus
  26 `+`, followed by the source <src>, followed
  27 by a colon `:`, followed by the destination ref <dst>.
  28 The colon can be omitted when <dst> is empty.  <src> is
  29 typically a ref, but it can also be a fully spelled hex object
  30 name.
  31 +
  32 `tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`;
  33 it requests fetching everything up to the given tag.
  34 +
  35 The remote ref that matches <src>
  36 is fetched, and if <dst> is not an empty string, an attempt
  37 is made to update the local ref that matches it.
  38 +
  39 Whether that update is allowed without `--force` depends on the ref
  40 namespace it's being fetched to, the type of object being fetched, and
  41 whether the update is considered to be a fast-forward. Generally, the
  42 same rules apply for fetching as when pushing, see the `<refspec>...`
  43 section of linkgit:git-push[1] for what those are. Exceptions to those
  44 rules particular to 'git fetch' are noted below.
  45 +
  46 Until Git version 2.20, and unlike when pushing with
  47 linkgit:git-push[1], any updates to `refs/tags/*` would be accepted
  48 without `+` in the refspec (or `--force`). When fetching, we promiscuously
  49 considered all tag updates from a remote to be forced fetches.  Since
  50 Git version 2.20, fetching to update `refs/tags/*` works the same way
  51 as when pushing. I.e. any updates will be rejected without `+` in the
  52 refspec (or `--force`).
  53 +
  54 Unlike when pushing with linkgit:git-push[1], any updates outside of
  55 `refs/{tags,heads}/*` will be accepted without `+` in the refspec (or
  56 `--force`), whether that's swapping e.g. a tree object for a blob, or
  57 a commit for another commit that's doesn't have the previous commit as
  58 an ancestor etc.
  59 +
  60 Unlike when pushing with linkgit:git-push[1], there is no
  61 configuration which'll amend these rules, and nothing like a
  62 `pre-fetch` hook analogous to the `pre-receive` hook.
  63 +
  64 As with pushing with linkgit:git-push[1], all of the rules described
  65 above about what's not allowed as an update can be overridden by
  66 adding an the optional leading `+` to a refspec (or using `--force`
  67 command line option). The only exception to this is that no amount of
  68 forcing will make the `refs/heads/*` namespace accept a non-commit
  69 object.
  70 +
  71 [NOTE]
  72 When the remote branch you want to fetch is known to
  73 be rewound and rebased regularly, it is expected that
  74 its new tip will not be descendant of its previous tip
  75 (as stored in your remote-tracking branch the last time
  76 you fetched).  You would want
  77 to use the `+` sign to indicate non-fast-forward updates
  78 will be needed for such branches.  There is no way to
  79 determine or declare that a branch will be made available
  80 in a repository with this behavior; the pulling user simply
  81 must know this is the expected usage pattern for a branch.
  82 ifdef::git-pull[]
  83 +
  84 [NOTE]
  85 There is a difference between listing multiple <refspec>
  86 directly on 'git pull' command line and having multiple
  87 `remote.<repository>.fetch` entries in your configuration
  88 for a <repository> and running a
  89 'git pull' command without any explicit <refspec> parameters.
  90 <refspec>s listed explicitly on the command line are always
  91 merged into the current branch after fetching.  In other words,
  92 if you list more than one remote ref, 'git pull' will create
  93 an Octopus merge.  On the other hand, if you do not list any
  94 explicit <refspec> parameter on the command line, 'git pull'
  95 will fetch all the <refspec>s it finds in the
  96 `remote.<repository>.fetch` configuration and merge
  97 only the first <refspec> found into the current branch.
  98 This is because making an
  99 Octopus from remote refs is rarely done, while keeping track
 100 of multiple remote heads in one-go by fetching more than one
 101 is often useful.
 102 endif::git-pull[]