stablesort: move parent range computation into its own method
Now that we have running code, we'll need to avoid too deep recursion. We
extract the piece dealing with the parent range before we write more code to
warm it.
#!/bin/bash
set -euox pipefail
unset GREP_OPTIONS
NOTOPIC="--config experimental.topic-mode=ignore"
compatbranches=`hg branches --quiet | grep 'mercurial-' | grep -v ':' | sort -n --reverse`
prev='stable'
for branch in $compatbranches; do
hg up $branch
hg merge $prev
hg commit -m "test-compat: merge $prev into $branch"
prev=$branch
done