Re: Simplify-by-decoration with decorate-refs-exclude

["René Scharfe" <l.s.r@web.de>]

Am 02.08.19 um 10:47 schrieb Étienne SERVAIS:
> Thus, when I enter
>
> ```
> git log --oneline --graph  --decorate=full --decorate-refs-exclude='refs/tags/<pattern>'
> ```
> The selected tags are properly excluded but once I add the
> `simplify-by-decoration` option
>
> ```
> git log --oneline --graph  --decorate=full --decorate-refs-exclude='refs/tags/<pattern>' --simplify-by-decoration
> ```
> The excluded tags pop back again.

Does this help?

-- >8 --
Subject: [PATCH] revision: load decorations lazily for --simplify-by-decoration

Let setup_revisions() and friends respect a filtered set of decoration
refs loaded by callers by postponing its own load_ref_decorations() call
to just before decorations are used to simplify history.  That function
only does any actual work the first time it is called.

This allows using the revision option --simplify-by-decoration together
with the log option --decorate-refs-exclude and having it simplify over
the restricted set of refs.

Reported-by: Étienne SERVAIS <etienne.servais@voucoux.fr>
Signed-off-by: René Scharfe <l.s.r@web.de>
---
 revision.c     |  8 +++++++-
 t/t4202-log.sh | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/revision.c b/revision.c
index 07412297f0..d3456c959b 100644
--- a/revision.c
+++ b/revision.c
@@ -633,6 +633,13 @@ static int rev_compare_tree(struct rev_info *revs,
 		return REV_TREE_OLD;

 	if (revs->simplify_by_decoration) {
+		/*
+		 * Load decorations lazily; later calls have no effect.
+		 * This gives callers a chance to load a restricted set
+		 * beforehand.
+		 */
+		load_ref_decorations(NULL, DECORATE_SHORT_REFS);
+
 		/*
 		 * If we are simplifying by decoration, then the commit
 		 * is worth showing if it has a tag pointing at it.
@@ -2063,7 +2070,6 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->simplify_by_decoration = 1;
 		revs->limited = 1;
 		revs->prune = 1;
-		load_ref_decorations(NULL, DECORATE_SHORT_REFS);
 	} else if (!strcmp(arg, "--date-order")) {
 		revs->sort_order = REV_SORT_BY_COMMIT_DATE;
 		revs->topo_order = 1;
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index c20209324c..bb66d1d93c 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -837,6 +837,21 @@ test_expect_success 'decorate-refs and decorate-refs-exclude' '
 	test_cmp expect.decorate actual
 '

+test_expect_success 'decorate-refs-exclude and simplify-by-decoration' '
+	cat >expect.decorate <<-\EOF &&
+	Merge-tag-reach (HEAD -> master)
+	reach (tag: reach, reach)
+	seventh (tag: seventh)
+	Merge-branch-tangle
+	Merge-branch-side-early-part-into-tangle (tangle)
+	tangle-a (tag: tangle-a)
+	EOF
+	git log -n6 --decorate=short --pretty="tformat:%f%d" \
+		--decorate-refs-exclude="*octopus*" \
+		--simplify-by-decoration >actual &&
+	test_cmp expect.decorate actual
+'
+
 test_expect_success 'log.decorate config parsing' '
 	git log --oneline --decorate=full >expect.full &&
 	git log --oneline --decorate=short >expect.short &&
--
2.22.0