use untrusted settings in hgweb The only exceptions are web.static and web.templates, since they can be used to get any file that is readable by the user running the CGI script. Other options can be (ab)used to increase the use of the cpu (allow_bz2) or of the bandwidth (server.uncompressed), but they're trusted anyway.

#!/bin/sh

hg init
echo "nothing" > a
hg add a
hg commit -m ancestor -d "1000000 0"
echo "something" > a
hg commit -m branch1 -d "1000000 0"
hg co 0
echo "something else" > a
hg commit -m branch2 -d "1000000 0"
HGMERGE=merge; export HGMERGE
hg merge 1
hg id
egrep -v ">>>|<<<" a
hg status