"bzr log --exclude-common-ancestry -rX..Y" inconsistent

[GuilhemBichot]

I have bzr.dev revno 5204.
I'm testing "bzr log -rX..Y --exclude-common-ancestry".
* With MySQL branches, the output doesn't contain X: I used
https://code.launchpad.net/~mysql/mysql-server/mysql-6.0-codebase at revid <email address hidden>
and then
bzr log -r tag:mysql-6.0.9..tag:mysql-6.0.10 --exclude-common-ancestry ,
and the revision with tag mysql-6.0.9 is not shown.
* In another test, the output contains X:
bzr init br1
cd br1
touch foo
bzr add .
bzr commit -m1
echo lkj > foo
bzr commit -m2
echo l > foo
bzr commit -m3
echo lmlll > foo
bzr commit -m4
bzr log -r3..4 --exclude-common-ancestry # shows 3 and 4
* I'm surprised that sometimes X is in the output and sometimes not.
The definition of this option, per "bzr help log", is "Display only the revisions that are not part of both ancestries", to me 3 is part of the ancestry of 3, and of 4, so should not be displaid.

[GuilhemBichot (guilhem-bichot)]

Hello. I don't understand the "Wishlist" state here. Is it really just my wish that it would always exclude or always include X, in -rX..Y? Isn't it rather a little bug that it sometimes excludes and other times includes X?

[Vincent Ladeuil (vila)]

The --exclude-common-ancestry implementation is obviously incomplete.
The consequences are not dramatic but this is definitely a bug.
Marking as Low instead.

[Vincent Ladeuil (vila)]

Just to confirm this happen only if X and Y are mainline revnos, I'll submit a fix asap.

[GuilhemBichot (guilhem-bichot)]

Thanks a lot Vincent, I tested that this fixes my testcase and does not degrade the case of "bzr log -r tag:mysql-6.0.9..tag:mysql-6.0.10 --exclude-common-ancestry".