Warn against removing published tags

[git-wiki.git] / pep-git.txt

diff --git a/pep-git.txt b/pep-git.txt
index dbe0b2a4a54b30132582dd841036bf053a64d1c4..fcdfc633980e8d538bcdc2cf21273e8782ae17fa 100644 (file)
--- a/pep-git.txt
+++ b/pep-git.txt
@@ -3,7 +3,7 @@ Title: Collecting information about git
 Version: $Revision$
 Last-Modified: $Date$
 Author: Oleg Broytman <phd@phdru.name>
 Version: $Revision$
 Last-Modified: $Date$
 Author: Oleg Broytman <phd@phdru.name>

-Status: Active
+Status: Draft

 Type: Informational
 Content-Type: text/x-rst
 Created: 01-Jun-2015
 Type: Informational
 Content-Type: text/x-rst
 Created: 01-Jun-2015


@@ -45,13 +45,13 @@ Git Tutorial: `part 1
 `Git workflows
 <https://www.kernel.org/pub/software/scm/git/docs/gitworkflows.html>`_.
 
 `Git workflows
 <https://www.kernel.org/pub/software/scm/git/docs/gitworkflows.html>`_.
 

+Advanced documentation
+----------------------
+

 `Git Magic
 <http://www-cs-students.stanford.edu/~blynn/gitmagic/index.html>`_,
 also with a number of translations.
 
 `Git Magic
 <http://www-cs-students.stanford.edu/~blynn/gitmagic/index.html>`_,
 also with a number of translations.
 

-Advanced documentation
-----------------------
-

 `Pro Git <https://git-scm.com/book>`_. The Book about git. Buy it at
 Amazon or download in PDF, mobi, or ePub form. Has translations to
 many different languages. Download Russian translation from `GArik
 `Pro Git <https://git-scm.com/book>`_. The Book about git. Buy it at
 Amazon or download in PDF, mobi, or ePub form. Has translations to
 many different languages. Download Russian translation from `GArik


@@ -85,9 +85,8 @@ MacOS X: use git installed with `XCode
 <http://sourceforge.net/projects/git-osx-installer/files/>`_ or
 install git with `Homebrew <http://brew.sh/>`_: ``brew install git``.
 
 <http://sourceforge.net/projects/git-osx-installer/files/>`_ or
 install git with `Homebrew <http://brew.sh/>`_: ``brew install git``.
 

-`git-cola <https://git-cola.github.io/index.html>`_ is a sleek and
-powerful Git GUI written in Python and GPL licensed. Linux, Windows,
-MacOS X.
+`git-cola <https://git-cola.github.io/index.html>`_ is a Git GUI
+written in Python and GPL licensed. Linux, Windows, MacOS X.

 
 `TortoiseGit <https://tortoisegit.org/>`_ is a Windows Shell Interface
 to Git based on TortoiseSVN; open source.
 
 `TortoiseGit <https://tortoisegit.org/>`_ is a Windows Shell Interface
 to Git based on TortoiseSVN; open source.


@@ -118,18 +117,23 @@ done something like that::
     $ cd python
     $ git branch v1 origin/v1
 
     $ cd python
     $ git branch v1 origin/v1
 

+The first command clones remote repository into local directory
+`python``, creates a new local branch v2, sets remotes/origin/v2 as
+its upstream remote-tracking branch and checks it out into the working
+directory.
+

 The last command creates a new local branch v1 and sets
 The last command creates a new local branch v1 and sets

-remotes/origin/v1 as its upstream remote branch.
+remotes/origin/v1 as its upstream remote-tracking branch.

 
 

-The same result can achieved with commands::
+The same result can be achieved with commands::

 
     $ git clone -b v1 http://git.python.org/python.git
     $ cd python
     $ git checkout --track origin/v2
 
 
     $ git clone -b v1 http://git.python.org/python.git
     $ cd python
     $ 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.
+The last command creates a new local branch v2, sets remotes/origin/v2
+as its upstream remote-tracking branch and checks it out into the
+working directory.

 
 
 Branches and branches
 
 
 Branches and branches


@@ -138,52 +142,49 @@ 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 line of
 commits (possibly with merges). And a branch is a label or a pointer
 Git terminology can be a bit misleading. Take, for example, the term
 "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. Lines of commits
-are by itself unnamed and are usually only lengthening and merging.
+assigned to a line of commits. It is important to distinguish when 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.
 
 
 Labels, on the other hand, can be created, moved, renamed and deleted
 freely.
 
 

-Remote repository and remote branches
-=====================================
+Remote repositories and remote branches
+=======================================

 
 

-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-tracking branches are branches (pointers to commits) 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). Remote-tracking branches live
+under ``remotes/REMOTE`` namespaces, e.g. ``remotes/origin/v2``.

 
 

-Remote branches, on the other hand, are branches (pointers to commits)
-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). Remote branches
-live under ``remotes/REMOTE`` namespaces, e.g. ``remotes/origin/v2``.
-
-To see the status of remote branches run::
+To see the status of remote-tracking branches run::

 
     $ git branch -rv
 
 
     $ git branch -rv
 

-To see local and remote branches (and tags) pointing to commits::
+To see local and remote-tracking branches (and tags) pointing to
+commits::

 
     $ git log --decorate
 
 
     $ git log --decorate
 

-You never do your own development on remote branches. You create a
-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.
+You never do your own development on remote-tracking branches. You
+create a local branch that has a remote branch as upstream and do
+development on that local branch. On push git pushes commits to the
+remote repo and updates remote-tracking branches, on pull git fetches
+commits from the remote repo, updates remote-tracking branches and
+fast-forwards, merges or rebases local branches.

 
 When you do an initial clone like this::
 
     $ git clone -b v1 http://git.python.org/python.git
 
 git clones remote repository ``http://git.python.org/python.git`` to
 
 When you do an initial clone like this::
 
     $ git clone -b v1 http://git.python.org/python.git
 
 git clones remote repository ``http://git.python.org/python.git`` to

-directory ``python``, creates remote branches, creates a local branch
-``v1``, configure it to track upstream remotes/origin/v1 branch and
-checks out ``v1`` into the working directory.
+directory ``python``, creates remote-tracking branches, creates a
+local branch ``v1``, configure it to track upstream remotes/origin/v1
+branch and checks out ``v1`` into the working directory.

 
 

-Updating local and remote branches
-----------------------------------
+Updating local and remote-tracking branches
+-------------------------------------------

 
 There is a major difference between
 
 
 There is a major difference between
 


@@ -199,14 +200,14 @@ and
 
 The first command fetches commits from the named BRANCH in the REMOTE
 repository that are not in your repository and leaves the id (the
 
 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).
+hash) of the head commit in file .git/FETCH_HEAD and
+updates remote-tracking branch.

 
 The second command fetches commits from the named BRANCH in the REMOTE
 repository that are not in your repository and updates both the local
 
 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.
+branch BRANCH and its upstream remote-tracking 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``.
 
 
 The first command is used internally by ``git pull``.
 


@@ -219,15 +220,15 @@ is equivalent to
 ::
 
     $ git fetch REMOTE BRANCH
 ::
 
     $ git fetch REMOTE BRANCH

-    $ git merge FETCH_HEAD # FETCH_HEAD is a literal here
+    $ 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::
 
 
 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 fetch origin v1:v1  # Update v1
+    $ git pull --rebase origin v2  # Update the current branch v2 using
+                                   # rebase instead of merge

     $ git merge v1
 
 If you have not yet pushed commits on ``v1``, though, the scenario has
     $ git merge v1
 
 If you have not yet pushed commits on ``v1``, though, the scenario has


@@ -257,6 +258,10 @@ or even
 
     $ git pull
 
 
     $ git pull
 

+Default remote repository for fetching/pulling is origin. Default set
+of references to fetch is calculated using matching algorithm: git
+fetches all branches having the same name on both ends.
+

 Push
 ''''
 
 Push
 ''''
 


@@ -267,17 +272,16 @@ run
 
     $ git push origin v1 v2
 
 
     $ git push origin v1 v2
 

-git guesses (knowing upstream remote branches) that you really want
-
-::
+git pushes local v1 to remote v1 and local v2 to remote v2. The same
+as::

 
     $ git push origin v1:v1 v2:v2
 
 
     $ 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,
+Git pushes commits to the remote repo and updates remote-tracking
+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
 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


@@ -296,6 +300,21 @@ or even
 
     $ git push
 
 
     $ git push
 

+Default remote repository for pushing is origin. Default set
+of references to push in git before 2.0 is calculated using matching
+algorithm: git pushes all branches having the same name on both ends.
+Default set of references to push in git 2.0+ is calculated using
+simple algorithm: git pushes the current branch back to its
+@{upstream}.
+
+To configure git before 2.0 to the new behaviour run::
+
+$ git config push.default simple
+
+To configure git 2.0+ to the old behaviour run::
+
+$ git config push.default matching
+

 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
 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


@@ -328,7 +347,8 @@ pushed). To push tags list them explicitly::
     $ git push origin tag 1.4.2
     $ git push origin v1 v2 tag 2.1.7
 
     $ git push origin tag 1.4.2
     $ git push origin v1 v2 tag 2.1.7
 

-Don't move tags with ``git tag -f`` after they have been published.
+Don't move tags with ``git tag -f`` or remove tags with ``git tag -d``
+after they have been published.

 
 
 Commit editing and caveats
 
 
 Commit editing and caveats


@@ -341,14 +361,14 @@ It is possible to recover from forced push but it's PITA for the
 entire team. Please avoid it.
 
 To see what commits have not been published yet compare the head of the
 entire team. Please avoid it.
 
 To see what commits have not been published yet compare the head of the

-branch with its upstream remote branch::
+branch with its upstream remote-tracking branch::

 
     $ git log origin/v2..
     $ git log origin/v1..v1
 
 
     $ git log origin/v2..
     $ git log origin/v1..v1
 

-For every branch that has an upstream remote branch git maintains an
-alias @{upstream} (short version @{u}), so the commands above can be
-given as::
+For every branch that has an upstream remote-tracking branch git
+maintains an alias @{upstream} (short version @{u}), so the commands
+above can be given as::

 
     $ git log @{u}..
     $ git log v1@{u}..v1
 
     $ git log @{u}..
     $ git log v1@{u}..v1


@@ -376,11 +396,41 @@ or shared repository.
 Undo
 ====
 
 Undo
 ====
 

-TODO: describe undo strategies: git reset, git revert, git checkout,
-git reflog. "Commit early, commit often".
+Whatever you do, don't panic. Almost anything in git can be undone.
+``git checkout``, for example, can be used to restore the content of
+file(s) to that one of a commit. Like this::
+
+    git checkout HEAD~ README
+
+The commands restores the contents of README file to the last but one
+commit in the current branch. By default a commit ID is simply HEAD;
+i.e. ``git checkout README`` restores README to the latest commit.
+
+(Do not use ``git checkout`` to view a content of a file in a commit,
+use ``git cat-file -p``; e.g. ``git cat-file -p HEAD~:path/to/README``).
+
+``git reset`` moves the head of the current branch. The head can be
+moved to point to any commit but it's often used to remove a commit or
+a few (preferably, non-pushed ones) from the top of the branch - that
+is, to move the branch backward in order to undo a few (non-pushed)
+commits.
+
+``git reset`` has three modes of operation - soft, hard and mixed.
+Default is mixed. ProGit `explains
+<https://git-scm.com/book/en/Git-Tools-Reset-Demystified>`_ the
+difference very clearly. Bare repositories don't have indices or
+working trees so in a bare repo only soft reset is possible.
+
+Mixed mode reset with a path or paths can be used to unstage changes -
+that is, to remove changes added with ``git add`` for committing. See
+`The Book <https://git-scm.com/book/en/v2/Git-Basics-Undoing-Things>`_
+for details about unstaging and other undo tricks.
+
+TODO: describe undo strategies: git reflog, git revert.
+"Commit early, commit often".

 
 How to undo a merge
 
 How to undo a merge

-https://kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.html
+https://www.kernel.org/pub/software/scm/git/docs/howto/revert-a-faulty-merge.html

 
 
 Merge or rebase?
 
 
 Merge or rebase?


@@ -400,7 +450,7 @@ recommends to use rebase when pulling, i.e. always do ``git pull
 --rebase`` or even configure automatic setup of rebase for every new
 branch::
 
 --rebase`` or even configure automatic setup of rebase for every new
 branch::
 

-    $ git config branch.autosetuprebase true
+    $ git config branch.autosetuprebase always

 
 and configure rebase for existing branches::
 
 
 and configure rebase for existing branches::
 


@@ -408,6 +458,7 @@ and configure rebase for existing branches::
 
 For example::
 
 
 For example::
 

+    $ git config branch.v1.rebase true

     $ git config branch.v2.rebase true
 
 After that ``git pull origin v2`` becomes equivalent to ``git pull
     $ git config branch.v2.rebase true
 
 After that ``git pull origin v2`` becomes equivalent to ``git pull


@@ -416,25 +467,25 @@ After that ``git pull origin v2`` becomes equivalent to ``git pull
 In case when merge is preferred it is recommended to create new
 commits in a separate feature or topic branch while using rebase to
 update the mainline branch. When the topic branch is ready merge it
 In case when merge is preferred it is recommended to create new
 commits in a separate feature or topic branch while using rebase to
 update the mainline branch. When the topic branch is ready merge it

-into mainline. To avoid a tedious task of resolving conflicts you can
-merge the topic branch to the mainline from time to time and switch
-back to the topic branch to continue working on it. The entire
-workflow would be something like::
+into mainline. To avoid a tedious task of resolving large number of
+conflicts at once you can merge the topic branch to the mainline from
+time to time and switch back to the topic branch to continue working
+on it. The entire workflow would be something like::

 
 

-    $ git checkout -b issue-42 # create and switch to a new branch
+    $ git checkout -b issue-42  # create a new issue branch and switch to it

         ...edit/test/commit...
     $ git checkout v2
         ...edit/test/commit...
     $ git checkout v2

-    $ git pull --rebase origin v2 # update v2 from the upstream
+    $ git pull --rebase origin v2  # update v2 from the upstream

     $ git merge issue-42
     $ git merge issue-42

-    $ git branch -d issue-42 # delete the topic branch
+    $ git branch -d issue-42  # delete the topic branch

     $ git push origin v2
 
 When the topic branch is deleted only the label is removed, commits
 are stayed in the database, they are now merged into v2::
 
     $ git push origin v2
 
 When the topic branch is deleted only the label is removed, commits
 are stayed in the database, they are now merged into v2::
 

-    --o--o--o--o--o--o-M-<v2 - it is the mainline branch
-            \         /
-             --*--*--*       - it is the topic branch, now unnamed
+    o--o--o--o--o--M--< v2 - the mainline branch
+        \         /
+         --*--*--*         - the topic branch, now unnamed

 
 The topic branch is deleted to avoid cluttering branch namespace with
 small topic branches. Information on what issue was fixed or what
 
 The topic branch is deleted to avoid cluttering branch namespace with
 small topic branches. Information on what issue was fixed or what


@@ -444,10 +495,10 @@ feature was implemented should be in the commit messages.
 Null-merges
 ===========
 
 Null-merges
 ===========
 

-Git has a builtin strategy for what Python core developers call
+Git has a builtin merge strategy for what Python core developers call

 "null-merge"::
 
 "null-merge"::
 

-    $ git merge -s ours v1 # null-merge v1 into v2
+    $ git merge -s ours v1  # null-merge v1 into v2

 
 
 ReReRe
 
 
 ReReRe


@@ -486,13 +537,20 @@ Database maintenance
 
 TODO: dangling objects, git gc, git repack.
 
 
 TODO: dangling objects, git gc, git repack.
 

+https://gcc.gnu.org/ml/gcc/2007-12/msg00165.html
+
+http://vcscompare.blogspot.ru/2008/06/git-repack-parameters.html
+

 
 Tips and tricks
 ===============
 
 TODO: sticky options; example: git grep -O.
 
 
 Tips and tricks
 ===============
 
 TODO: sticky options; example: git grep -O.
 

+TODO: tricky options; example: git log -p3.
+

 TODO: bash/zsh completion, bash/zsh prompt.
 TODO: bash/zsh completion, bash/zsh prompt.

+https://git.kernel.org/cgit/git/git.git/tree/contrib/completion

 
 
 git on server
 
 
 git on server


@@ -500,6 +558,11 @@ git on server
 
 TODO: anonymous access; git over ssh; gitolite; gitweb; cgit; gitlab.
 
 
 TODO: anonymous access; git over ssh; gitolite; gitweb; cgit; gitlab.
 

+http://gitolite.com/gitolite/index.html
+
+https://git.kernel.org/cgit/git/git.git/tree/gitweb
+
+http://git.zx2c4.com/cgit/

 
 From Mercurial to git
 =====================
 
 From Mercurial to git
 =====================