branchmap: server should not advertise secret changeset in branchmap (Issue3303)
Discovery now use an overlay above branchmap to prune invisible "secret"
changeset from branchmap.
To minimise impact on the code during the code freeze, this is achieve by
recomputing non-secret heads on the fly when any secret changeset exists. This
is a computation heavy approach similar to the one used for visible heads. But
few sever should contains secret changeset anyway. See comment in code for more
robust approach.
On local repo the wrapper is applied explicitly while the wire-protocol take
care of wrapping branchmap call in a transparent way. This could be unified by
the Peter Arrenbrecht and Sune Foldager proposal of a `peer` object.
An inappropriate `(+i heads)` may still appear when pushing new changes on a
repository with secret changeset. (see Issue3394 for details)
$ hg init t
$ cd t
$ echo 1 > a
$ hg ci -qAm "first"
$ hg cp a b
$ hg mv a c
$ echo 2 >> b
$ echo 2 >> c
$ hg ci -qAm "second"
$ hg co -C 0
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo 0 > a
$ echo 1 >> a
$ hg ci -qAm "other"
$ hg merge --debug
searching for copies back to rev 1
unmatched files in other:
b
c
all copies found (* = to merge, ! = divergent):
c -> a *
b -> a *
checking for directory renames
resolving manifests
overwrite: False, partial: False
ancestor: b8bf91eeebbc, local: add3f11052fa+, remote: 17c05bb7fcb6
a: remote moved to c -> m
a: remote moved to b -> m
preserving a for resolve of b
preserving a for resolve of c
removing a
updating: a 1/2 files (50.00%)
picked tool 'internal:merge' for b (binary False symlink False)
merging a and b to b
my b@add3f11052fa+ other b@17c05bb7fcb6 ancestor a@b8bf91eeebbc
premerge successful
updating: a 2/2 files (100.00%)
picked tool 'internal:merge' for c (binary False symlink False)
merging a and c to c
my c@add3f11052fa+ other c@17c05bb7fcb6 ancestor a@b8bf91eeebbc
premerge successful
0 files updated, 2 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
file b
$ cat b
0
1
2
file c
$ cat c
0
1
2