git-merge-changelog: add documentation

[Bruno Haible]

Hi,

Brian Gough found out how to make use of the git-merge-changelog program for
'git'. Let me add his findings as documentation. Thanks a lot, Brian!


2010-08-14  Brian Gough  <address@hidden>
            Bruno Haible  <address@hidden>

        git-merge-changelog: add doc relating to use with bzr and hg.
        * lib/git-merge-changelog.c: Add comments regarding bzr, hg, diff3.

*** lib/git-merge-changelog.c.orig      Sat Aug 14 19:56:29 2010
--- lib/git-merge-changelog.c   Sat Aug 14 19:50:16 2010
***************
*** 40,62 ****
   */
  
  /* Installation:
     $ gnulib-tool --create-testdir --dir=/tmp/testdir123 git-merge-changelog
     $ cd /tmp/testdir123
     $ ./configure
     $ make
     $ make install
-    - Add to .git/config of the checkout (or to your $HOME/.gitconfig) the 
lines
  
!         [merge "merge-changelog"]
!                 name = GNU-style ChangeLog merge driver
!                 driver = /usr/local/bin/git-merge-changelog %O %A %B
  
!    - In every directory that contains a ChangeLog file, add a file
!      '.gitattributes' with this line:
  
!         ChangeLog    merge=merge-changelog
  
!      (See "man 5 gitattributes" for more info.)
   */
  
  /* Calling convention:
--- 40,91 ----
   */
  
  /* Installation:
+ 
     $ gnulib-tool --create-testdir --dir=/tmp/testdir123 git-merge-changelog
     $ cd /tmp/testdir123
     $ ./configure
     $ make
     $ make install
  
!    Additionally, for git users:
!      - Add to .git/config of the checkout (or to your $HOME/.gitconfig) the
!        lines
! 
!           [merge "merge-changelog"]
!                   name = GNU-style ChangeLog merge driver
!                   driver = /usr/local/bin/git-merge-changelog %O %A %B
! 
!      - In every directory that contains a ChangeLog file, add a file
!        '.gitattributes' with this line:
! 
!           ChangeLog    merge=merge-changelog
! 
!        (See "man 5 gitattributes" for more info.)
  
!    Additionally, for bzr users:
!      - Install the 'extmerge' bzr plug-in listed at
!          <http://doc.bazaar.canonical.com/plugins/en/index.html>
!          <http://wiki.bazaar.canonical.com/BzrPlugins>
!      - Add to your $HOME/.bazaar/bazaar.conf the line
  
!           external_merge = git-merge-changelog %b %T %o
! 
!      - Then, to merge a conflict in a ChangeLog file, use
! 
!           $ bzr extmerge ChangeLog
! 
!    Additionally, for hg users:
!      - Add to your $HOME/.hgrc a couple of lines in a section [merge-tools].
!        See <http://www.selenic.com/mercurial/hgrc.5.html> section merge-tools
!        for reference.
!  */
  
! /* Use as an alternative to 'diff3':
!    git-merge-changelog performs the same role as "diff3 -m", just with
!    reordered arguments:
!      $ git-merge-changelog %O %A %B
!    is comparable to
!      $ diff3 -m %A %O %B
   */
  
  /* Calling convention: