view README @ 990:5007e0bdeed2

Fix long-standing excessive file merges

Since switching to the multihead approach, we've been creating
excessive file-level merges where files are marked as merged with
their ancestors.

This explicitly checks at commit time whether the two parent versions
are linearly related, and if so, reduces the file check-in to a
non-merge. Then the file is compared against the remaining parent,
and, if equal, skips check-in of that file (as it's not changed).

Since we're not checking in all files that were different between
versions, we no longer need to mark so many files for merge. This
removes most of the 'm' state marking as well.

Finally, it is possible to do a tree-level merge with no file-level
changes. This will happen if one user changes file A and another
changes file B. Thus, if we have have two parents, we allow commit to
proceed even if there are no file-level changes.

MERCURIAL QUICK-START

Setting up Mercurial:

 Note: some distributions fails to include bits of distutils by
 default, you'll need python-dev to install. You'll also need a C
 compiler and a 3-way merge tool like merge, tkdiff, or kdiff3.

 First, unpack the source:

 $ tar xvzf mercurial-<ver>.tar.gz
 $ cd mercurial-<ver>

 To install system-wide:

 $ python setup.py install   # change python to python2.3 if 2.2 is default

 To install in your home directory (~/bin and ~/lib, actually), run:

 $ python2.3 setup.py install --home=~
 $ export PYTHONPATH=${HOME}/lib/python  # (or lib64/ on some systems)
 $ export PATH=${HOME}/bin:$PATH         # add these to your .bashrc

 And finally:

 $ hg                                    # test installation, show help

 If you get complaints about missing modules, you probably haven't set
 PYTHONPATH correctly.

Setting up a Mercurial project:

 $ cd project/
 $ hg init         # creates .hg
 $ hg addremove    # add all unknown files and remove all missing files
 $ hg commit       # commit all changes, edit changelog entry

 Mercurial will look for a file named .hgignore in the root of your
 repository which contains a set of regular expressions to ignore in
 file paths.

Branching and merging:

 $ hg clone linux linux-work    # create a new branch
 $ cd linux-work
 $ <make changes>
 $ hg commit
 $ cd ../linux
 $ hg pull ../linux-work     # pull changesets from linux-work
 $ hg update -m              # merge the new tip from linux-work into
                             # our working directory
 $ hg commit                 # commit the result of the merge

Importing patches:

 Fast:
 $ patch < ../p/foo.patch
 $ hg addremove
 $ hg commit

 Faster:
 $ patch < ../p/foo.patch
 $ hg commit `lsdiff -p1 ../p/foo.patch`

 Fastest:
 $ cat ../p/patchlist | xargs hg import -p1 -b ../p 

Exporting a patch:

 (make changes)
 $ hg commit
 $ hg tip
 28237:747a537bd090880c29eae861df4d81b245aa0190
 $ hg export 28237 > foo.patch    # export changeset 28237

Network support:

 # pull from the primary Mercurial repo
 foo$ hg clone http://selenic.com/hg/ 
 foo$ cd hg

 # export your current repo via HTTP with browsable interface
 foo$ hg serve -n "My repo" -p 80
 
 # pushing changes to a remote repo with SSH
 foo$ hg push ssh://[e-mail]/~/hg/

 # merge changes from a remote machine
 bar$ hg pull http://foo/
 bar$ hg update -m        # merge changes into your working directory

 # Set up a CGI server on your webserver
 foo$ cp hgweb.cgi ~/public_html/hg/index.cgi
 foo$ emacs ~/public_html/hg/index.cgi # adjust the defaults

For more info:

 Documentation in doc/
 Mercurial website at http://selenic.com/mercurial
 Mercurial wiki at http://selenic.com/mercurial/wiki