X-Git-Url: https://git.phdru.name/?a=blobdiff_plain;ds=sidebyside;f=pep-git.txt;h=ef0274c4317bb2e7eac473ac07a63260dbfd59a6;hb=30c29e008eb934501f7ee4d2e73a8279f1511988;hp=0a120b479eb391b1063c1ae7fea15b77be7d76ea;hpb=eb27b379d58ea18f4ab2f16cf8a5fc4ec7d6f471;p=git-wiki.git
diff --git a/pep-git.txt b/pep-git.txt
index 0a120b4..ef0274c 100644
--- a/pep-git.txt
+++ b/pep-git.txt
@@ -14,7 +14,7 @@ Abstract
This Informational PEP collects information about git. There is, of
course, a lot of documentation for git, so the PEP concentrates on
-more complex issues, topics and scenarios.
+more complex issues, scenarios and topics.
The plan is to extend the PEP in the future collecting information
about equivalence of Mercurial and git scenarios to help migrating
@@ -75,24 +75,30 @@ Download and installation
Unix users: download and install using your package manager.
Microsoft Windows: download `git-for-windows
-`_.
+`_ or `msysGit
+`_.
MacOS X: use git installed with `XCode
-`_ or download
+`_ or download from
+`MacPorts `_ or
`git-osx-installer
-`_.
+`_ or
+install git with `Homebrew `_: ``brew install git``.
+
+`Atlassins's SourceTree `_ is a free
+Git and Mercurial GUI client for Windows or Mac.
Initial configuration
---------------------
This simple code is often appears in documentation, but it is
-important so let repeat it here::
+important so let repeat it here. Git marks every commit with author
+and committer names/emails, so configure your real name and preferred
+email::
$ git config --global user.name "User Name"
$ git config --global user.email user.name@example.org
-Put your real name and preferred email.
-
Examples in this PEP
====================
@@ -101,53 +107,67 @@ Examples of git commands in this PEP use the following approach. It is
supposed that you, the user, works with a local repository named
``python`` that has an upstream remote repo named ``origin``. Your
local repo has two branches ``v1`` and ``v2``. For most examples the
-currently checked out branch is ``v2``. That is, it's assumed you did
-something like that::
+currently checked out branch is ``v2``. That is, it's assumed you have
+done something like that::
+
+ $ git clone -b v2 http://git.python.org/python.git
+ $ cd python
+ $ git branch v1 origin/v1
+
+The last command creates a new local branch v1 and sets
+remotes/origin/v1 as its upstream remote branch.
+
+The same result can achieved with commands::
$ git clone -b v1 http://git.python.org/python.git
$ cd python
- $ git fetch origin v2:v2
- $ git checkout -b v2
+ $ git checkout --track origin/v2
+
+The last command creates a new local branch v2, sets
+remotes/origin/v2 as its upstream remote branch and checks it out into
+the working directory.
Branches and branches
=====================
Git terminology can be a bit misleading. Take, for example, the term
-"branch". In git it has two meanings. A branch is a directed chain of
-commits (possible with merges). And a branch is a label or a pointer
+"branch". In git it has two meanings. A branch is a directed line of
+commits (possibly with merges). And a branch is a label or a pointer
assigned to a line of commits. It is important to differentiate when
-you talk about commits and when about their labels. Chains of commits
-are unnamed and are usually only lengthening. Labels, on the other
-hand, can be created, moved, renamed and deleted freely.
+you talk about commits and when about their labels. Lines of commits
+are by itself unnamed and are usually only lengthening and merging.
+Labels, on the other hand, can be created, moved, renamed and deleted
+freely.
Remote repository and remote branches
=====================================
-Another example of misleading terminology. A remote repository is
-really remote, you access it via network (well, a remote repository
-can be on your local disk, but it's still remote because it's not the
-current repo).
+Another example of slightly misleading terminology. Remote
+repositories are really remote, you access them via network (well, a
+remote repository can be on your local disk, but it's still remote
+because it's not the current repo).
Remote branches, on the other hand, are branches (pointers to commits)
-in your local repository. They are there for git to remember what
+in your local repository. They are there for you to remember what
branches and commits have been pulled from and pushed to what remote
-repos (you can pull from and push to many remotes).
+repos (you can pull from and push to many remotes). Remote branches
+live under ``remotes/REMOTE`` namespaces, e.g. ``remotes/origin/v2``.
-To see the status of remote branches::
+To see the status of remote branches run::
$ git branch -rv
-To see local and remote branches (and tags) pointing to commits run::
+To see local and remote branches (and tags) pointing to commits::
$ git log --decorate
You never do your own development on remote branches. You create a
-local branch that has a remote branch as an upstream and do
-development on that local branch. On push git updates remote branches,
-and on pull git updates remote branches and fast-forwards, merges or
-rebases local branches.
+local branch that has a remote branch as upstream and do development
+on that local branch. On push git updates remote branches, and on pull
+git updates remote branches and fast-forwards, merges or rebases local
+branches.
When you do an initial clone like this::
@@ -157,12 +177,138 @@ git clones remote repository ``http://git.python.org/python.git`` to
directory ``python``, creates remote branches and checks out branch
``v1`` into the working directory.
+Updating local and remote branches
+----------------------------------
+
+There is a major difference between
+
+::
+
+ $ git fetch REMOTE BRANCH
+
+and
+
+::
+
+ $ git fetch REMOTE BRANCH:BRANCH
+
+The first command fetches commits from the named BRANCH in the REMOTE
+repository that are not in your repository and leaves the id (the
+hash) of the head commit in file .git/FETCH_HEAD. But it doesn't
+update any branch (doesn't move any pointer).
+
+The second command fetches commits from the named BRANCH in the REMOTE
+repository that are not in your repository and updates both the local
+branch BRANCH and its upstream remote branch. But it refuses to update
+branches in case of non-fast-forward. And it refuses to update the
+current branch.
+
+The first command is used internally by ``git pull``.
+
+::
+
+ $ git pull REMOTE BRANCH
+
+is equivalent to
+
+::
+
+ $ git fetch REMOTE BRANCH
+ $ git merge FETCH_HEAD # FETCH_HEAD is a literal here
+
+Certainly, BRANCH in that case should be your current branch. If you
+want to merge a different branch into your current branch first update
+that non-current branch and then merge::
+
+ $ git fetch origin v1:v1 # Update v1
+ $ git pull --rebase origin v2 # Update the current branch v2 using
+ # rebase instead of merge
+ $ git merge v1
+
+It is possible to configure git to make it fetch/pull a few branches
+or all branches at once, so you can simply run
+
+::
+
+ $ git pull origin
+
+or even
+
+::
+
+ $ git pull
+
+Push
+''''
+
+Pushing is a bit simpler. There is only one command ``push``. When you
+run
+
+::
+
+ $ git push origin v1 v2
+
+git guesses (knowing upstream remote branches) that you really want
+
+::
+
+ $ git push origin v1:v1 v2:v2
+
+Git pushes commits to the remote repo and updates remote branches. Git
+refuses to push commits that aren't fast-forwardable. You can
+force-push anyway, but please remember - you can force-push to your
+own repositories but don't force-push to public or shared repos. If
+you find git refuses to push commits that aren't fast-forwardable,
+better fetch and merge commits from the remote repo (or rebase your
+commits on top of the fetched commits), then push. Only force-push if
+you know what you do and why you do it. See the section `Commit
+editing and caveats`_ below.
+
+It is possible to configure git to make it push a few branches or all
+branches at once, so you can simply run
+
+::
+
+ $ git push origin
+
+or even
+
+::
+
+ $ git push
+
+Git refuses to push a branch if it's the current branch in the remote
+non-bare repository: git refuses to update remote working directory.
+You really should push only to bare repositories. For non-bare
+repositories git prefers pull-based workflow.
+
+Tags
+''''
+
+Git automatically fetches tags that point to commits being fetched
+during fetch/pull. To fetch all tags (and commits they point to) run
+``git fetch --tags origin``. To fetch some specific tags fetch them
+explicitly::
+
+ $ git fetch origin tag NAME1 tag NAME2...
+
+For example::
+
+ $ git fetch origin tag 1.4.2 tag 2.1.7
+
+Git doesn't automatically pushes tags. That allows you to have private
+tags (lightweight tags are also private for a repo, they cannot be
+pushed). To push tags list them explicitly::
+
+ $ git push origin tag 1.4.2
+ $ git push origin v1 v2 tag 2.1.7
+
Commit editing and caveats
==========================
A warning not to edit published (pushed) commits also appears in
-documentation but it's also repeated here as it's very important.
+documentation but it's repeated here anyway as it's very important.
It is possible to recover from forced push but it's PITA for the
entire team. Please avoid it.
@@ -197,7 +343,7 @@ safely edit, remove, reorder, combine and split commits that hasn't
been pushed yet. You can even push commits to your own (backup) repo,
edit them later and force-push edited commits to replace what has
already been pushed. Not a problem until commits are in a public
-repository.
+or shared repository.
Undo
@@ -224,15 +370,8 @@ Staging area aka index is a distinguishing feature of git. See
Wiki.
-Advanced configuration
-======================
-
-Line endings
-------------
-
-Git has builtin mechanisms to handle line endings.
-
-TODO: describe crlf configuration and .gitattributes.
+Merge or rebase?
+================
Null-merges
@@ -244,6 +383,23 @@ Git has a builtin strategy for what Python core developers call
$ git merge -s ours v1 # null-merge v1 into v2
+ReReRe
+======
+
+https://git-scm.com/book/en/Git-Tools-Rerere
+
+
+Advanced configuration
+======================
+
+Line endings
+------------
+
+Git has builtin mechanisms to handle line endings.
+
+TODO: describe crlf configuration and .gitattributes.
+
+
Database maintenance
====================