Merge from trunk; up to 2013-02-18T01:30:27Z!monnier@iro.umontreal.ca.

6 files changed, 119 insertions, 5 deletions

diff --git a/admin/notes/bzr b/admin/notes/bzr
index 50eaf3710ee..f35ff95f9d6 100644
--- a/admin/notes/bzr
+++ b/admin/notes/bzr
@@ -182,6 +182,71 @@ where revision N+1 is the one where file was removed.
 You could also try `bzr add --file-ids-from', if you have a copy of
 another branch where file still exists.
 
+* Undoing a commit (uncommitting)
+
+It is possible to undo/remove a bzr commit (ie, to uncommit).
+Only do this if you really, really, need to.  For example, if you
+somehow made a commit that triggers a bug in bzr itself.
+Don't do it because you made a typo in a commit or the log.
+
+If you do need to do this, do it as soon as possible, because the
+longer you leave it, the more work is involved.
+
+0. First, tell emacs-devel that you are going to do this, and suggest
+people not commit anything to the affected branch for the duration.
+
+In the following, replace USER with your Savannah username, and
+BRANCH with the name of the branch.
+Let's assume that revno 100 is the bad commit, and that there have
+been two more commits after that (because nothing is ever easy).
+
+1. Ensure your copy of the branch is up-to-date (for a bound
+branch, bzr up; for an unbound branch, bzr pull) and has no local
+changes (bzr st).
+
+2. Make a record of the commits you are going to undo:
+bzr diff -c 102 > /tmp/102.diff
+etc
+
+Also record the commit message, author, and any --fixes information.
+
+3. Most Emacs branches are set up to prevent just this kind of thing.
+So we need to disable that protection:
+
+bzr config append_revisions_only=False \
+  -d bzr+ssh://USER@bzr.savannah.gnu.org/emacs/BRANCH/
+
+4. Undo the commits:
+bzr uncommit -r -4
+
+This will show the commits it is going to undo, and prompt you to confirm.
+
+5. If using an unbound branch:
+bzr push --overwrite
+
+6. Now, replay the commits you just undid (obviously, fix whatever it
+was in the bad commit that caused the problem):
+
+patch -p0 < /tmp/100.diff
+bzr commit --author ... --fixes ... -F /tmp/100.log
+etc
+
+7. If using an unbound branch:
+bzr push
+
+8. Finally, re-enable the branch protection:
+bzr config append_revisions_only=True \
+  -d bzr+ssh://USER@bzr.savannah.gnu.org/emacs/BRANCH/
+
+9. Tell emacs-devel that it is ok to use the branch again.
+Anyone with local changes should back them up before doing anything.
+
+For a bound branch, bzr up will convert any of the undone commits to a
+pending merge. Just bzr revert these away.
+
+For an unbound branch, bzr pull will complain about diverged branches
+and refuse to do anything.  Use bzr pull --overwrite.
+
 * Loggerhead
 
 Loggerhead is the bzr tool for viewing a repository over http (similar
@@ -202,3 +267,52 @@ For example, on RHEL6 I needed:
   yum --enablerepo=epel install python-simpletal
 
 Then point your web-browser to http://127.0.0.1:8080/ .
+
+* Bisecting
+
+This is a semi-automated way to find the revision that introduced a bug.
+
+First, get the bzr bisect plugin if you do not have it already:
+
+  cd ~/.bazaar/plugins
+  bzr branch lp:bzr-bisect bisect
+
+`bzr help bisect' should work now.
+
+It's probably simplest to make a new copy of the branch to work in
+from this point onwards.
+
+Identify the last known "good" revision where the relevant issue is
+NOT present (e.g. maybe Emacs 24.1).  Let's say this is revision 1000.
+
+  bzr bisect start
+  bzr bisect no -r 1000
+
+At this point, bzr will switch to the mid-point of revision 1000 and
+the current revision.  If you know that the issue was definitely
+present in some specific revision (say 2000), you can use:
+
+  bzr bisect yes -r 2000
+
+Now bzr switches to revision 1500.
+
+Now test whether the issue is present.  You might need to rebuild
+Emacs to do this, or if you know the problem is in a specific Lisp
+file, you might be able to get away with just loading that one file in
+current Emacs.
+
+If the issue is present, use
+
+  bzr bisect yes
+
+If it is not, use
+
+  bzr bisect no
+
+Repeat until you zero-in on the specific revision.
+
+When finished, use
+
+  bzr bisect reset
+
+or simply delete the entire branch if you created it just for this.
diff --git a/admin/notes/copyright b/admin/notes/copyright
index 173ff83343a..3a404b69678 100644
--- a/admin/notes/copyright
+++ b/admin/notes/copyright
@@ -1,4 +1,4 @@
-Copyright (C) 2007-2012  Free Software Foundation, Inc.
+Copyright (C) 2007-2013 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
 
diff --git a/admin/notes/font-backend b/admin/notes/font-backend
index ec2dc11345b..cdf2001580d 100644
--- a/admin/notes/font-backend
+++ b/admin/notes/font-backend
@@ -1,4 +1,4 @@
-Copyright (C) 2002-2012  Free Software Foundation, Inc.
+Copyright (C) 2002-2013 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
 
diff --git a/admin/notes/lel-TODO b/admin/notes/lel-TODO
index 139aa09e919..2c6d86a4ffd 100644
--- a/admin/notes/lel-TODO
+++ b/admin/notes/lel-TODO
@@ -1,6 +1,6 @@
 Some lisp/emacs-lisp/ Features and Where They Are Documented
 
-Copyright (C) 2007-2012 Free Software Foundation, Inc.
+Copyright (C) 2007-2013 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
 
diff --git a/admin/notes/multi-tty b/admin/notes/multi-tty
index 5408b9a3d00..c4edd3abc93 100644
--- a/admin/notes/multi-tty
+++ b/admin/notes/multi-tty
@@ -1,6 +1,6 @@
 -*- coding: utf-8; mode: text; -*-
 
-Copyright (C) 2007-2012  Free Software Foundation, Inc.
+Copyright (C) 2007-2013 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
 From README.multi-tty in the multi-tty branch.
diff --git a/admin/notes/unicode b/admin/notes/unicode
index dda6ec4cc93..21704c78a00 100644
--- a/admin/notes/unicode
+++ b/admin/notes/unicode
@@ -1,6 +1,6 @@
                                             -*-mode: text; coding: latin-1;-*-
 
-Copyright (C) 2002-2012 Free Software Foundation, Inc.
+Copyright (C) 2002-2013 Free Software Foundation, Inc.
 See the end of the file for license conditions.
 
 Problems, fixmes and other unicode-related issues