absorb: preserve changesets which were already empty
Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty
changesets or drop them if they become empty. If there’s a changeset that’s
empty, it must be a deliberate choice of the user. At least it shouldn’t be
absorb’s responsibility to prune them. The fact that changesets that became
empty during absorb are pruned, is unaffected by this.
This case was found while writing patches which make it possible to configure
absorb and rebase to not drop empty changesets. Even without having such config
set, I think it’s valuable to preserve changesets which were already empty.
#require no-windows
$ . "$TESTDIR/remotefilelog-library.sh"
generaldelta to generaldelta interactions with bundle2 but legacy clients
without changegroup2 support
$ cat > testcg2.py << EOF
> import sys
> from mercurial import changegroup, registrar, util
> cmdtable = {}
> command = registrar.command(cmdtable)
> @command('testcg2', norepo=True)
> def testcg2(ui):
> if not util.safehasattr(changegroup, 'cg2packer'):
> sys.exit(80)
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> testcg2 = $TESTTMP/testcg2.py
> EOF
$ hg testcg2 || exit 80
$ cat > disablecg2.py << EOF
> from mercurial import changegroup, error, util
> deleted = False
> def reposetup(ui, repo):
> global deleted
> if deleted:
> return
> packermap = changegroup._packermap
> # protect against future changes
> if len(packermap) != 3:
> raise error.Abort('packermap has %d versions, expected 3!' % len(packermap))
> for k in ['01', '02', '03']:
> if not packermap.get(k):
> raise error.Abort("packermap doesn't have key '%s'!" % k)
>
> del packermap['02']
> deleted = True
> EOF
$ hg init master
$ grep generaldelta master/.hg/requires
generaldelta
$ cd master
preferuncompressed = False so that we can make both generaldelta and non-generaldelta clones
$ cat >> .hg/hgrc <<EOF
> [remotefilelog]
> server=True
> [experimental]
> bundle2-exp = True
> [server]
> preferuncompressed = False
> EOF
$ echo x > x
$ hg commit -qAm x
$ cd ..
$ hgcloneshallow ssh://user@dummy/master shallow -q --pull --config experimental.bundle2-exp=True
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ cd shallow
$ cat >> .hg/hgrc << EOF
> [extensions]
> disablecg2 = $TESTTMP/disablecg2.py
> EOF
$ cd ../master
$ echo y > y
$ hg commit -qAm y
$ cd ../shallow
$ hg pull -u
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files
new changesets d34c38483be9
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
$ echo a > a
$ hg commit -qAm a
$ hg push
pushing to ssh://user@dummy/master
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files