branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
Test update.requiredest
$ cd $TESTTMP
$ cat >> $HGRCPATH <<EOF
> [commands]
> update.requiredest = True
> EOF
$ hg init repo
$ cd repo
$ echo a >> a
$ hg commit -qAm aa
$ hg up
abort: you must specify a destination
(for example: hg update ".::")
[10]
$ hg up .
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ HGPLAIN=1 hg up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --config commands.update.requiredest=False up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ..
Check update.requiredest interaction with pull --update
$ hg clone repo clone
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo
$ echo a >> a
$ hg commit -qAm aa
$ cd ../clone
$ hg pull --update
abort: update destination required by configuration
(use hg pull followed by hg update DEST)
[10]
$ cd ..
update.requiredest should silent the "hg update" text after pull
$ hg init repo1
$ cd repo1
$ hg pull ../repo
pulling from ../repo
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets 8f0162e483d0:048c2cb95949