Some valgrind patches

[Mikael Magnusson <mikachu@xxxxxxxxx>]

These are roughly ordered from most to least sure I am that it's a
complete / correct fix. The last 2 in particular I would like comments
on. I'll commit everything up to patch 11 unless someone objects and
nothing after unless someone says it's the right thing to do.

(This is the first time I send more than one patch out at once with git
send-email so hopefully it works right.)