Building tcpdump with USE_INET6=no

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

In src/external/bsd/tcpdump/bin/Makefile we have provisions to 
build with USE_IENT6=no

.if (${USE_INET6} != "no")
SRCS+= \
print-babel.c \
print-ip6opts.c \
print-dhcp6.c \
print-frag6.c \
print-icmp6.c \
print-ip6.c \
print-ospf6.c \
print-rt6.c

CPPFLAGS+=-DHAVE_OS_IPV6_SUPPORT=1
.endif

Unfortunately, tcpdump sources do not work fine with this, and the
build will complain about undefined symbolsa:
ip6_print
nextproto6_cksum
dhcp6_print
babel_print.

The code logic does not use them of course, hence I created a inet6_stub;c
file with empty definitions of the functions ,and added them to SRCS
if USE_INET6=no. It works, but oly if inet6_stub.c is in  
src/external/bsd/tcpdump/dist, otherwise it will not find it at link
time. 

I understand dist is for upstream distribution. How can I fix that 
properly?


-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost