Subject: [PATCH] name-rev: Fix tag lookup on repository with mixed types of tags

From: [email-masked]
Date: Wed, 18 Oct 2017 16:24:20 +0300

From: Orgad Shaneh <[email-masked]>

Commit 7550424804 (name-rev: include taggerdate in considering the best
name) introduced a bug in name-rev.

If a repository has both annotated and non-annotated tags, annotated
tag will always win, even if it was created decades after the commit.

Consider a repository that always used non-annotated tags, and at some
point started using annotated tags - name-rev --tags will return the
first annotated tags for all the old commits (in our repository it is
followed by ~5067 for one commit, or by ~120^2~21^2~88^2~87 for
another...). This is obviously not what the user expects.

There was an attempt to fix this in ef1e74065, but it is not enough.

The taggerdate should only be matched if *both tags* have it.

Signed-off-by: Orgad Shaneh <[email-masked]>
---
 builtin/name-rev.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/builtin/name-rev.c b/builtin/name-rev.c
index 9e088ebd11..dc9eaf21fa 100644
--- a/builtin/name-rev.c
+++ b/builtin/name-rev.c
@@ -35,7 +35,7 @@ static int is_better_name(struct rev_name *name,
 	 */
 	if (from_tag && name->from_tag)
 		return (name->taggerdate > taggerdate ||
-			(name->taggerdate == taggerdate &&
+			((taggerdate == TIME_MAX || name->taggerdate == taggerdate) &&
 			 name->distance > distance));
 
 	/*
@@ -53,7 +53,7 @@ static int is_better_name(struct rev_name *name,
 		return name->distance > distance;
 
 	/* ... or tiebreak to favor older date */
-	if (name->taggerdate != taggerdate)
+	if (taggerdate != TIME_MAX && name->taggerdate != taggerdate)
 		return name->taggerdate > taggerdate;
 
 	/* keep the current one if we cannot decide */
@@ -90,7 +90,8 @@ static void name_rev(struct commit *commit,
 				  generation, distance, from_tag)) {
 copy_data:
 		name->tip_name = tip_name;
-		name->taggerdate = taggerdate;
+		if (taggerdate != TIME_MAX)
+			name->taggerdate = taggerdate;
 		name->generation = generation;
 		name->distance = distance;
 		name->from_tag = from_tag;
-- 
2.14.2.windows.3