evolve: refactor the code which swap two nodes (in divergence resolution) I see that we are using the code to swap the "divergent" and "other" node; and updating the evolvestate accordingly at many places in divergence resolution. This patch extract that code to a function. Although I don't have strong opinion on this patch. It's a volunteered patch to remove some redundancy.

#!/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