+(0) Decide what to base your work on.
+
+In general, always base your work on the oldest branch that your
+change is relevant to.
+
+ - A bugfix should be based on 'maint' in general. If the bug is not
+ present in 'maint', base it on 'master'. For a bug that's not yet
+ in 'master', find the topic that introduces the regression, and
+ base your work on the tip of the topic.
+
+ - A new feature should be based on 'master' in general. If the new
+ feature depends on a topic that is in 'pu', but not in 'master',
+ base your work on the tip of that topic.
+
+ - Corrections and enhancements to a topic not yet in 'master' should
+ be based on the tip of that topic. If the topic has not been merged
+ to 'next', it's alright to add a note to squash minor corrections
+ into the series.
+
+ - In the exceptional case that a new feature depends on several topics
+ not in 'master', start working on 'next' or 'pu' privately and send
+ out patches for discussion. Before the final merge, you may have to
+ wait until some of the dependent topics graduate to 'master', and
+ rebase your work.
+
+To find the tip of a topic branch, run "git log --first-parent
+master..pu" and look for the merge commit. The second parent of this
+commit is the tip of the topic branch.