git-merge man page on Mandriva

Man page or keyword search:  
man Server   17060 pages
apropos Keyword Search (all sections)
Output format
Mandriva logo
[printable version]

GIT-MERGE(1)			  Git Manual			  GIT-MERGE(1)

NAME
       git-merge - Join two or more development histories together

SYNOPSIS
       git merge [-n] [--stat] [--no-commit] [--squash]
	       [-s <strategy>] [-X <strategy-option>]
	       [--[no-]rerere-autoupdate] [-m <msg>] <commit>...
       git merge <msg> HEAD <commit>...

DESCRIPTION
       Incorporates changes from the named commits (since the time their
       histories diverged from the current branch) into the current branch.
       This command is used by git pull to incorporate changes from another
       repository and can be used by hand to merge changes from one branch
       into another.

       Assume the following history exists and the current branch is "master":

		     A---B---C topic
		    /
	       D---E---F---G master

       Then "git merge topic" will replay the changes made on the topic branch
       since it diverged from master (i.e., E) until its current commit (C) on
       top of master, and record the result in a new commit along with the
       names of the two parent commits and a log message from the user
       describing the changes.

		     A---B---C topic
		    /	      \
	       D---E---F---G---H master

       The second syntax (<msg> HEAD <commit>...) is supported for historical
       reasons. Do not use it from the command line or in new scripts. It is
       the same as git merge -m <msg> <commit>....

       Warning: Running git merge with uncommitted changes is discouraged:
       while possible, it leaves you in a state that is hard to back out of in
       the case of a conflict.

OPTIONS
       --commit, --no-commit
	   Perform the merge and commit the result. This option can be used to
	   override --no-commit.

	   With --no-commit perform the merge but pretend the merge failed and
	   do not autocommit, to give the user a chance to inspect and further
	   tweak the merge result before committing.

       --ff, --no-ff
	   Do not generate a merge commit if the merge resolved as a
	   fast-forward, only update the branch pointer. This is the default
	   behavior of git-merge.

	   With --no-ff Generate a merge commit even if the merge resolved as
	   a fast-forward.

       --log, --no-log
	   In addition to branch names, populate the log message with one-line
	   descriptions from the actual commits that are being merged.

	   With --no-log do not list one-line descriptions from the actual
	   commits being merged.

       --stat, -n, --no-stat
	   Show a diffstat at the end of the merge. The diffstat is also
	   controlled by the configuration option merge.stat.

	   With -n or --no-stat do not show a diffstat at the end of the
	   merge.

       --squash, --no-squash
	   Produce the working tree and index state as if a real merge
	   happened (except for the merge information), but do not actually
	   make a commit or move the HEAD, nor record $GIT_DIR/MERGE_HEAD to
	   cause the next git commit command to create a merge commit. This
	   allows you to create a single commit on top of the current branch
	   whose effect is the same as merging another branch (or more in case
	   of an octopus).

	   With --no-squash perform the merge and commit the result. This
	   option can be used to override --squash.

       --ff-only
	   Refuse to merge and exit with a non-zero status unless the current
	   HEAD is already up-to-date or the merge can be resolved as a
	   fast-forward.

       -s <strategy>, --strategy=<strategy>
	   Use the given merge strategy; can be supplied more than once to
	   specify them in the order they should be tried. If there is no -s
	   option, a built-in list of strategies is used instead (git
	   merge-recursive when merging a single head, git merge-octopus
	   otherwise).

       -X <option>, --strategy-option=<option>
	   Pass merge strategy specific option through to the merge strategy.

       --summary, --no-summary
	   Synonyms to --stat and --no-stat; these are deprecated and will be
	   removed in the future.

       -q, --quiet
	   Operate quietly.

       -v, --verbose
	   Be verbose.

       -m <msg>
	   Set the commit message to be used for the merge commit (in case one
	   is created). The git fmt-merge-msg command can be used to give a
	   good default for automated git merge invocations.

       --rerere-autoupdate, --no-rerere-autoupdate
	   Allow the rerere mechanism to update the index with the result of
	   auto-conflict resolution if possible.

       <commit>...
	   Commits, usually other branch heads, to merge into our branch. You
	   need at least one <commit>. Specifying more than one <commit>
	   obviously means you are trying an Octopus.

PRE-MERGE CHECKS
       Before applying outside changes, you should get your own work in good
       shape and committed locally, so it will not be clobbered if there are
       conflicts. See also git-stash(1). git pull and git merge will stop
       without doing anything when local uncommitted changes overlap with
       files that git pull/git merge may need to update.

       To avoid recording unrelated changes in the merge commit, git pull and
       git merge will also abort if there are any changes registered in the
       index relative to the HEAD commit. (One exception is when the changed
       index entries are in the state that would result from the merge
       already.)

       If all named commits are already ancestors of HEAD, git merge will exit
       early with the message "Already up-to-date."

FAST-FORWARD MERGE
       Often the current branch head is an ancestor of the named commit. This
       is the most common case especially when invoked from git pull: you are
       tracking an upstream repository, you have committed no local changes,
       and now you want to update to a newer upstream revision. In this case,
       a new commit is not needed to store the combined history; instead, the
       HEAD (along with the index) is updated to point at the named commit,
       without creating an extra merge commit.

       This behavior can be suppressed with the --no-ff option.

TRUE MERGE
       Except in a fast-forward merge (see above), the branches to be merged
       must be tied together by a merge commit that has both of them as its
       parents.

       A merged version reconciling the changes from all branches to be merged
       is committed, and your HEAD, index, and working tree are updated to it.
       It is possible to have modifications in the working tree as long as
       they do not overlap; the update will preserve them.

       When it is not obvious how to reconcile the changes, the following
       happens:

	1. The HEAD pointer stays the same.

	2. The MERGE_HEAD ref is set to point to the other branch head.

	3. Paths that merged cleanly are updated both in the index file and in
	   your working tree.

	4. For conflicting paths, the index file records up to three versions:
	   stage 1 stores the version from the common ancestor, stage 2 from
	   HEAD, and stage 3 from MERGE_HEAD (you can inspect the stages with
	   git ls-files -u). The working tree files contain the result of the
	   "merge" program; i.e. 3-way merge results with familiar conflict
	   markers <<< === >>>.

	5. No other changes are made. In particular, the local modifications
	   you had before you started merge will stay the same and the index
	   entries for them stay as they were, i.e. matching HEAD.

       If you tried a merge which resulted in complex conflicts and want to
       start over, you can recover with git reset --merge.

HOW CONFLICTS ARE PRESENTED
       During a merge, the working tree files are updated to reflect the
       result of the merge. Among the changes made to the common ancestor’s
       version, non-overlapping ones (that is, you changed an area of the file
       while the other side left that area intact, or vice versa) are
       incorporated in the final result verbatim. When both sides made changes
       to the same area, however, git cannot randomly pick one side over the
       other, and asks you to resolve it by leaving what both sides did to
       that area.

       By default, git uses the same style as that is used by "merge" program
       from the RCS suite to present such a conflicted hunk, like this:

	   Here are lines that are either unchanged from the common
	   ancestor, or cleanly resolved because only one side changed.
	   <<<<<<< yours:sample.txt
	   Conflict resolution is hard;
	   let´s go shopping.
	   =======
	   Git makes conflict resolution easy.
	   >>>>>>> theirs:sample.txt
	   And here is another line that is cleanly resolved or unmodified.

       The area where a pair of conflicting changes happened is marked with
       markers <<<<<<<, =======, and >>>>>>>. The part before the ======= is
       typically your side, and the part afterwards is typically their side.

       The default format does not show what the original said in the
       conflicting area. You cannot tell how many lines are deleted and
       replaced with Barbie’s remark on your side. The only thing you can tell
       is that your side wants to say it is hard and you’d prefer to go
       shopping, while the other side wants to claim it is easy.

       An alternative style can be used by setting the "merge.conflictstyle"
       configuration variable to "diff3". In "diff3" style, the above conflict
       may look like this:

	   Here are lines that are either unchanged from the common
	   ancestor, or cleanly resolved because only one side changed.
	   <<<<<<< yours:sample.txt
	   Conflict resolution is hard;
	   let´s go shopping.
	   |||||||
	   Conflict resolution is hard.
	   =======
	   Git makes conflict resolution easy.
	   >>>>>>> theirs:sample.txt
	   And here is another line that is cleanly resolved or unmodified.

       In addition to the <<<<<<<, =======, and >>>>>>> markers, it uses
       another ||||||| marker that is followed by the original text. You can
       tell that the original just stated a fact, and your side simply gave in
       to that statement and gave up, while the other side tried to have a
       more positive attitude. You can sometimes come up with a better
       resolution by viewing the original.

HOW TO RESOLVE CONFLICTS
       After seeing a conflict, you can do two things:

       ·   Decide not to merge. The only clean-ups you need are to reset the
	   index file to the HEAD commit to reverse 2. and to clean up working
	   tree changes made by 2. and 3.; git-reset --hard can be used for
	   this.

       ·   Resolve the conflicts. Git will mark the conflicts in the working
	   tree. Edit the files into shape and git add them to the index. Use
	   git commit to seal the deal.

       You can work through the conflict with a number of tools:

       ·   Use a mergetool.  git mergetool to launch a graphical mergetool
	   which will work you through the merge.

       ·   Look at the diffs.  git diff will show a three-way diff,
	   highlighting changes from both the HEAD and MERGE_HEAD versions.

       ·   Look at the diffs from each branch.	git log --merge -p <path> will
	   show diffs first for the HEAD version and then the MERGE_HEAD
	   version.

       ·   Look at the originals.  git show :1:filename shows the common
	   ancestor, git show :2:filename shows the HEAD version, and git show
	   :3:filename shows the MERGE_HEAD version.

EXAMPLES
       ·   Merge branches fixes and enhancements on top of the current branch,
	   making an octopus merge:

	       $ git merge fixes enhancements

       ·   Merge branch obsolete into the current branch, using ours merge
	   strategy:

	       $ git merge -s ours obsolete

       ·   Merge branch maint into the current branch, but do not make a new
	   commit automatically:

	       $ git merge --no-commit maint

	   This can be used when you want to include further changes to the
	   merge, or want to write your own merge commit message.

	   You should refrain from abusing this option to sneak substantial
	   changes into a merge commit. Small fixups like bumping
	   release/version name would be acceptable.

MERGE STRATEGIES
       The merge mechanism (git-merge and git-pull commands) allows the
       backend merge strategies to be chosen with -s option. Some strategies
       can also take their own options, which can be passed by giving
       -X<option> arguments to git-merge and/or git-pull.

       resolve
	   This can only resolve two heads (i.e. the current branch and
	   another branch you pulled from) using a 3-way merge algorithm. It
	   tries to carefully detect criss-cross merge ambiguities and is
	   considered generally safe and fast.

       recursive
	   This can only resolve two heads using a 3-way merge algorithm. When
	   there is more than one common ancestor that can be used for 3-way
	   merge, it creates a merged tree of the common ancestors and uses
	   that as the reference tree for the 3-way merge. This has been
	   reported to result in fewer merge conflicts without causing
	   mis-merges by tests done on actual merge commits taken from Linux
	   2.6 kernel development history. Additionally this can detect and
	   handle merges involving renames. This is the default merge strategy
	   when pulling or merging one branch.

	   The recursive strategy can take the following options:

	   ours
	       This option forces conflicting hunks to be auto-resolved
	       cleanly by favoring our version. Changes from the other tree
	       that do not conflict with our side are reflected to the merge
	       result.

	       This should not be confused with the ours merge strategy, which
	       does not even look at what the other tree contains at all. It
	       discards everything the other tree did, declaring our history
	       contains all that happened in it.

	   theirs
	       This is opposite of ours.

	   subtree[=path]
	       This option is a more advanced form of subtree strategy, where
	       the strategy makes a guess on how two trees must be shifted to
	       match with each other when merging. Instead, the specified path
	       is prefixed (or stripped from the beginning) to make the shape
	       of two trees to match.

       octopus
	   This resolves cases with more than two heads, but refuses to do a
	   complex merge that needs manual resolution. It is primarily meant
	   to be used for bundling topic branch heads together. This is the
	   default merge strategy when pulling or merging more than one
	   branch.

       ours
	   This resolves any number of heads, but the resulting tree of the
	   merge is always that of the current branch head, effectively
	   ignoring all changes from all other branches. It is meant to be
	   used to supersede old development history of side branches. Note
	   that this is different from the -Xours option to the recursive
	   merge strategy.

       subtree
	   This is a modified recursive strategy. When merging trees A and B,
	   if B corresponds to a subtree of A, B is first adjusted to match
	   the tree structure of A, instead of reading the trees at the same
	   level. This adjustment is also done to the common ancestor tree.

CONFIGURATION
       merge.conflictstyle
	   Specify the style in which conflicted hunks are written out to
	   working tree files upon merge. The default is "merge", which shows
	   a <<<<<<< conflict marker, changes made by one side, a =======
	   marker, changes made by the other side, and then a >>>>>>> marker.
	   An alternate style, "diff3", adds a ||||||| marker and the original
	   text before the ======= marker.

       merge.log
	   Whether to include summaries of merged commits in newly created
	   merge commit messages. False by default.

       merge.renameLimit
	   The number of files to consider when performing rename detection
	   during a merge; if not specified, defaults to the value of
	   diff.renameLimit.

       merge.stat
	   Whether to print the diffstat between ORIG_HEAD and the merge
	   result at the end of the merge. True by default.

       merge.tool
	   Controls which merge resolution program is used by git-
	   mergetool(1). Valid built-in values are: "kdiff3", "tkdiff",
	   "meld", "xxdiff", "emerge", "vimdiff", "gvimdiff", "diffuse",
	   "ecmerge", "tortoisemerge", "p4merge", "araxis" and "opendiff". Any
	   other value is treated is custom merge tool and there must be a
	   corresponding mergetool.<tool>.cmd option.

       merge.verbosity
	   Controls the amount of output shown by the recursive merge
	   strategy. Level 0 outputs nothing except a final error message if
	   conflicts were detected. Level 1 outputs only conflicts, 2 outputs
	   conflicts and file changes. Level 5 and above outputs debugging
	   information. The default is level 2. Can be overridden by the
	   GIT_MERGE_VERBOSITY environment variable.

       merge.<driver>.name
	   Defines a human-readable name for a custom low-level merge driver.
	   See gitattributes(5) for details.

       merge.<driver>.driver
	   Defines the command that implements a custom low-level merge
	   driver. See gitattributes(5) for details.

       merge.<driver>.recursive
	   Names a low-level merge driver to be used when performing an
	   internal merge between common ancestors. See gitattributes(5) for
	   details.

       branch.<name>.mergeoptions
	   Sets default options for merging into branch <name>. The syntax and
	   supported options are the same as those of git merge, but option
	   values containing whitespace characters are currently not
	   supported.

SEE ALSO
       git-fmt-merge-msg(1), git-pull(1), gitattributes(5), git-reset(1), git-
       diff(1), git-ls-files(1), git-add(1), git-rm(1), git-mergetool(1)

AUTHOR
       Written by Junio C Hamano <gitster@pobox.com[1]>

DOCUMENTATION
       Documentation by Junio C Hamano and the git-list
       <git@vger.kernel.org[2]>.

GIT
       Part of the git(1) suite

NOTES
	1. gitster@pobox.com
	   mailto:gitster@pobox.com

	2. git@vger.kernel.org
	   mailto:git@vger.kernel.org

Git 1.7.1			  12/16/2010			  GIT-MERGE(1)
[top]

List of man pages available for Mandriva

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net