tests/library-infinitepush.sh

rust-revlog: fix RevlogEntry.data() for NULL_REVISION

Before this change, the pseudo-entry returned by `Revlog.get_entry` for
`NULL_REVISION` would trigger errors in application code using it.

For example, this fixes a crash spotted with changelog data
while implementing RHGitaly: `Changelog.data_for_rev(-1)` was already
returning the pseudo content as expected, e.g., for `hg log`, but
`Changelog.entry_for_rev(-1).data()` would still crash with
"corrupted revlog, hash check failed for revision -1". There is
an added test for this scenario.

scratchnodes() {
  for node in `find ../repo/.hg/scratchbranches/index/nodemap/* | sort`; do
     echo ${node##*/} `cat $node`
  done
}

scratchbookmarks() {
  for bookmark in `find ../repo/.hg/scratchbranches/index/bookmarkmap/* -type f | sort`; do
     echo "${bookmark##*/bookmarkmap/} `cat $bookmark`"
  done
}

setupcommon() {
  cat >> $HGRCPATH << EOF
[extensions]
infinitepush=
[infinitepush]
branchpattern=re:scratch/.*
deprecation-abort=no
deprecation-message=yes

EOF
}

setupserver() {
cat >> .hg/hgrc << EOF
[infinitepush]
server=yes
indextype=disk
storetype=disk
reponame=babar
EOF
}