I would like to suggest that we change the names used for patches in
pkgsrc.
Currently, their names are patch-[a-z][a-z] where the names are more
or less chosen randomly; when upgrading, usually care is taken to use
the same patch name to modify the same file as before (mkpatches(1)
from pkgtools/pkgdiff does that automatically).
I suggest we starting from now on, we use the name
patch-path_relative_to_wrksrc_filename instead, i.e. run the path of
the name of the file to patch through
sed -e "s,_,__,g" -e "s,/,_,g"
and prefix "patch-".