[PATCH v3 0/4] log: speed up --follow following renames for non-linear history

[Miklos Vajna <vmiklos@collabora.com>]

Hi Junio,

On Mon, Oct 19, 2026 at 08:11:05AM +0200, Miklos Vajna <vmiklos@collabora.com> wrote:
> This leads to a larger patch: should I extract the "rethink the
> approach" and the new tests to separate patches or it doesn't matter?

Here is a series where I split the changes into 4 patches: add more
tests, a refactor, then your suggestion to start over (with one more
test) and finally the speedup.

Thanks,

Miklos

Miklos Vajna (4):
  t4219: test more --follow cases across merges
  log: extract showing the remerge/combined diff of a merge commit
  log: simplify --follow following renames for non-linear history
  log: speed up --follow following renames for non-linear history

 log-tree.c                  | 201 +++++++++++++++++++++++++-----------
 t/t4219-log-follow-merge.sh | 128 +++++++++++++++++++++++
 2 files changed, 271 insertions(+), 58 deletions(-)

Interdiff against v2:
diff --git a/t/t4219-log-follow-merge.sh b/t/t4219-log-follow-merge.sh
index 9616ac64ed..c8474ed151 100755
--- a/t/t4219-log-follow-merge.sh
+++ b/t/t4219-log-follow-merge.sh
@@ -144,6 +144,22 @@ do
 	'
 done
 
+test_expect_success '--follow follows renames through a fork with -m' '
+	git -C diamond log --follow -m --pretty=tformat:%s path >log &&
+	grep "^[A-Z]: " log | sort >actual &&
+	cat >expect <<-\EOF &&
+	A: add path0
+	B: modify path0 on upper
+	C: modify path0 on lower
+	M: merge with rename to path
+	M: merge with rename to path
+	X: rename path0 to path1
+	Y: rename path0 to path2
+	Z: modify path
+	EOF
+	test_cmp expect actual
+'
+
 # Build a merge that takes the renamed path from the second parent, while the
 # first parent only has the old path. $2 decides which side is committed first,
 # which decides the walk order.
-- 
2.56.0