Order of canonical upgrade sequence

[Chris Rees]

Hi all!

Back in 2005, when Alexander Leidinger wrote the make delete-old
target, he documented the order of upgrade such that it should be run
before mergemaster [1];

#  7.  `make installworld'
#  8.  `make delete-old'
#  9.  `mergemaster'

I have merged the delete-old section of the Handbook into the
upgrading chapter, and independently decided to put mergemaster first,
because I thought it would be safer, but checked here before I
committed.

I think that steps 8 and 9 should be reversed, because of the
possibility of an unbootable system being made, when an rc script
references an executable that has just been removed for example.

I cannot think of an example where the system is left
unbootable/damaged if make delete-old is run after mergemaster.

What do people think of the patch at [2]?

Chris

[1] http://svnweb.freebsd.org/base/head/Makefile?r1=148329&r2=148330&

[2] http://www.bayofrum.net/~crees/patches/delete-old-order.diff