[Rpm-maint] upgrade process

[Tom Brown]

When an rpm is upgraded is the existing package removed before or after 
the post section of the package that is replacing it?

I ask because in my %post of a package a symlink gets created. This 
symlink is also removed if the package is removed so in the %postun

If i install the rpm the symlink is fine but if i upgrade the package 
the symlink is no longer there so i wonder if its being caught by the 
removal of the preceding package?

any clues?

thanks

%post

if [ -h /usr/java/latest ] ; then
        rm -f /usr/java/latest ;
fi

ln -s /usr/java/jdk%{version} /usr/java/latest

%postun

if [ -h /usr/java/latest ] ; then
        rm -f /usr/java/latest ;
fi