sparse: clean up config signature code
Before, 0 was being used as the default signature value and we cast
the int to a string. We also handled I/O exceptions manually.
The new code uses cfs.tryread() so we always feed data into the
hasher. The empty string does hash and and should be suitable
for input into a cache key.
The changes made the code simple enough that the separate checksum
function could be inlined.
# this file holds the definitions that are used in various bzr tests
TERM=dumb; export TERM
echo '[extensions]' >> $HGRCPATH
echo 'convert = ' >> $HGRCPATH
glog()
{
hg log -G --template '{rev}@{branch} "{desc|firstline}" files: {files}\n' "$@"
}
manifest()
{
echo "% manifest of $2"
hg -R $1 manifest -v -r $2
}