admin/notes/bzr

   1 NOTES ON COMMITTING TO EMACS'S BAZAAR REPO    -*- outline -*-
   2
   3 * Install changes only on one branch, let them get merged elsewhere if needed.
   4 In particular, install bug-fixes only on the release branch (if there
   5 is one) and let them get synced to the trunk; do not install them by
   6 hand on the trunk as well.  E.g. if there is an active "emacs-23" branch
   7 and you have a bug-fix appropriate for the next Emacs-23.x release,
   8 install it only on the emacs-23 branch, not on the trunk as well.
   9
  10 Installing things manually into more than one branch makes merges more
  11 difficult.
  12
  13 http://lists.gnu.org/archive/html/emacs-devel/2010-03/msg01124.html
  14
  15 * Backporting a bug-fix from the trunk to a branch (e.g. "emacs-23").
  16 Label the commit as a backport, e.g. by starting the commit message with
  17 "Backport:".  This is helpful for the person merging the release branch
  18 to the trunk.
  19
  20 http://lists.gnu.org/archive/html/emacs-devel/2010-05/msg00262.html
  21
  22 * Installing changes from your personal branches.
  23 If your branch has only a single commit, or many different real
  24 commits, it is fine to do a merge.  If your branch has only a very
  25 small number of "real" commits, but several "merge from trunks", it is
  26 preferred that you take your branch's diff, apply it to the trunk, and
  27 commit directly, not merge.  This keeps the history cleaner.
  28
  29 In general, when working on some feature in a separate branch, it is
  30 preferable not to merge from trunk until you are done with the
  31 feature.  Unless you really need some change that was done on the
  32 trunk while you were developing on the branch, you don't really need
  33 those merges; just merge once, when you are done with the feature, and
  34 Bazaar will take care of the rest.  Bazaar is much better in this than
  35 CVS, so interim merges are unnecessary.
  36
  37 Or use shelves; or rebase; or do something else.  See the thread for
  38 yet another fun excursion into the exciting world of version control.
  39
  40 http://lists.gnu.org/archive/html/emacs-devel/2010-04/msg00086.html
  41
  42 * Installing changes from gnulib
  43 Some of the files in Emacs are copied from gnulib.  To synchronize
  44 these files from the version of gnulib that you have checked out into
  45 a sibling directory of your branch, type "make sync-from-gnulib"; this
  46 will check out the latest version of gnulib if there is no sibling
  47 directory already.  It is a good idea to run "bzr status" afterwards,
  48 so that if a gnulib module added a file, you can record the new file
  49 using "bzr add".  After synchronizing from gnulib, do a "make" in the
  50 usual way.
  51
  52 To change the set of gnulib modules, change the GNULIB_MODULES
  53 variable in the top-level Makefile.in, and then run:
  54
  55   ./config.status
  56   make sync-from-gnulib
  57   bzr status
  58
  59 The last command will mention files that may need to be added using
  60 "bzr add".  If you remove a gnulib module, or if a gnulib module
  61 removes a file, then remove the corresponding files by hand.
  62
  63 * How to merge changes from emacs-23 to trunk
  64
  65 The following description uses bound branches, presumably it works in
  66 a similar way with unbound ones.
  67
  68 1) Get clean, up-to-date copies of the emacs-23 and trunk branches.
  69 Check for any uncommitted changes with bzr status.
  70
  71 2) M-x cd /path/to/trunk
  72
  73 3) load admin/bzrmerge.el
  74
  75 4) M-x bzrmerge RET /path/to/emacs-23 RET
  76
  77 It will prompt about revisions that should be skipped, based on the
  78 regexp in bzrmerge-missing.  If there are more revisions that you know
  79 need skipping, you'll have to do that by hand.
  80
  81 5) It will stop if there are any conflicts. Resolve them.
  82 Using smerge-mode, there are menu items to skip to the next conflict,
  83 and to take either the trunk, branch, or both copies.
  84
  85 6) After resolving all conflicts, you might need to run the command
  86 again if there are more revisions still to merge.
  87 You can commit either before you do this (eg if you had a lot of
  88 conflicts to resolve and don't want to get confused), or refrain from
  89 committing until bzrmerge has merged all revisions.
  90
  91 Before committing, check bzr status and bzr diff output.
  92
  93 Note that ChangeLog entries are automatically merged to the top with
  94 today's date, but you still might want to check them to see that too
  95 much is not being included.