Re: [PATCH 3/3] merge-base: find fork-point outside partial reflog

[Jeff King]

On Thu, Sep 14, 2017 at 03:15:20PM +0200, Michael J Gruber wrote:

> In fork-point mode, merge-base adds the commit at refname to a list of
> candidates to walk from only when the reflog is empty. Therefore, it
> fails to find merge bases that are descendants of the most recent reflog
> entry.
> 
> Add the commit at the tip unconditionally so that a merge base on the
> history of refname is found in any case, independent of the state of the
> reflog.

OK, so the reflog we are interested in here is one where the tip commit
is not mentioned. I'm not sure how one gets into that state, but I agree
it makes sense to act as if it's there.

-Peff

[PATCH 3/3] merge-base: find fork-point outside partial reflog

[Michael J Gruber]

In fork-point mode, merge-base adds the commit at refname to a list of
candidates to walk from only when the reflog is empty. Therefore, it
fails to find merge bases that are descendants of the most recent reflog
entry.

Add the commit at the tip unconditionally so that a merge base on the
history of refname is found in any case, independent of the state of the
reflog.

Signed-off-by: Michael J Gruber 
---
 builtin/merge-base.c  | 2 +-
 t/t6010-merge-base.sh | 8 
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index 926a7615ea..b5b4cf7eac 100644
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -174,7 +174,7 @@ static int handle_fork_point(int argc, const char **argv)
revs.initial = 1;
for_each_reflog_ent(refname, collect_one_reflog_ent, );
 
-   if (!revs.nr && !get_oid(refname, ))
+   if (!get_oid(refname, ))
add_one_commit(, );
 
for (i = 0; i < revs.nr; i++)
diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh
index 850463d4f2..78342896c7 100755
--- a/t/t6010-merge-base.sh
+++ b/t/t6010-merge-base.sh
@@ -275,6 +275,14 @@ test_expect_success '--fork-point works with merge-base 
outside reflog' '
test_cmp expect actual
 '
 
+test_expect_success '--fork-point works with merge-base outside partial 
reflog' '
+   git -c core.logallrefupdates=true branch partial-reflog base &&
+   git rev-parse no-reflog >.git/refs/heads/partial-reflog &&
+   git rev-parse no-reflog >expect &&
+   git merge-base --fork-point partial-reflog no-reflog >actual &&
+   test_cmp expect actual
+'
+
 test_expect_success 'merge-base --octopus --all for complex tree' '
# Best common ancestor for JE, JAA and JDD is JC
# JE
-- 
2.14.1.712.gda4591c8a2