Merge branch 'jc/merge-tag-object'

"git merge $(git rev-parse v1.8.2)" behaved quite differently from
"git merge v1.8.2" as if v1.8.2 were written as v1.8.2^0 and did
not pay much attention to the annotated tag payload.

This makes the code notice the type of the tag object, in addition
to the dwim_ref() based classification the current code uses
(i.e. the name appears in refs/tags/) to decide when to special
case merging of tags.

* jc/merge-tag-object:
  t6200: test message for merging of an annotated tag
  t6200: use test_config/test_unconfig
  merge: a random object may not necssarily be a commit

2 files changed, 81 insertions, 32 deletions

diff --git a/builtin/merge.c b/builtin/merge.c
index 7c8922c8b0..0d94d89e74 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -516,6 +516,19 @@ static void merge_name(const char *remote, struct strbuf *msg)
 		strbuf_release(&line);
 		goto cleanup;
 	}
+
+	if (remote_head->util) {
+		struct merge_remote_desc *desc;
+		desc = merge_remote_util(remote_head);
+		if (desc && desc->obj && desc->obj->type == OBJ_TAG) {
+			strbuf_addf(msg, "%s\t\t%s '%s'\n",
+				    sha1_to_hex(desc->obj->sha1),
+				    typename(desc->obj->type),
+				    remote);
+			goto cleanup;
+		}
+	}
+
 	strbuf_addf(msg, "%s\t\tcommit '%s'\n",
 		sha1_to_hex(remote_head->object.sha1), remote);
 cleanup:
diff --git a/t/t6200-fmt-merge-msg.sh b/t/t6200-fmt-merge-msg.sh
index 992c2a0467..f73eceabfb 100755
--- a/t/t6200-fmt-merge-msg.sh
+++ b/t/t6200-fmt-merge-msg.sh
@@ -112,8 +112,8 @@ test_expect_success '[merge] summary/log configuration' '
 	  Common #1
 	EOF
 
-	git config merge.log true &&
-	test_might_fail git config --unset-all merge.summary &&
+	test_config merge.log true &&
+	test_unconfig merge.summary &&
 
 	git checkout master &&
 	test_tick &&
@@ -121,8 +121,8 @@ test_expect_success '[merge] summary/log configuration' '
 
 	git fmt-merge-msg <.git/FETCH_HEAD >actual1 &&
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary true &&
+	test_unconfig merge.log &&
+	test_config merge.summary true &&
 
 	git checkout master &&
 	test_tick &&
@@ -134,11 +134,6 @@ test_expect_success '[merge] summary/log configuration' '
 	test_cmp expected actual2
 '
 
-test_expect_success 'setup: clear [merge] configuration' '
-	test_might_fail git config --unset-all merge.log &&
-	test_might_fail git config --unset-all merge.summary
-'
-
 test_expect_success 'setup FETCH_HEAD' '
 	git checkout master &&
 	test_tick &&
@@ -248,14 +243,14 @@ test_expect_success 'fmt-merge-msg -m' '
 	  Common #1
 	EOF
 
-	test_might_fail git config --unset merge.log &&
-	test_might_fail git config --unset merge.summary &&
+	test_unconfig merge.log &&
+	test_unconfig merge.summary &&
 	git checkout master &&
 	git fetch "$(pwd)" left &&
 	git fmt-merge-msg -m "Sync with left" <.git/FETCH_HEAD >actual &&
 	git fmt-merge-msg --log -m "Sync with left" \
 					<.git/FETCH_HEAD >actual.log &&
-	git config merge.log true &&
+	test_config merge.log true &&
 	git fmt-merge-msg -m "Sync with left" \
 					<.git/FETCH_HEAD >actual.log-config &&
 	git fmt-merge-msg --no-log -m "Sync with left" \
@@ -290,29 +285,29 @@ test_expect_success 'setup: expected shortlog for two branches' '
 '
 
 test_expect_success 'shortlog for two branches' '
-	git config merge.log true &&
-	test_might_fail git config --unset-all merge.summary &&
+	test_config merge.log true &&
+	test_unconfig merge.summary &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
 	git fmt-merge-msg <.git/FETCH_HEAD >actual1 &&
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary true &&
+	test_unconfig merge.log &&
+	test_config merge.summary true &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
 	git fmt-merge-msg <.git/FETCH_HEAD >actual2 &&
 
-	git config merge.log yes &&
-	test_might_fail git config --unset-all merge.summary &&
+	test_config merge.log yes &&
+	test_unconfig merge.summary &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
 	git fmt-merge-msg <.git/FETCH_HEAD >actual3 &&
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
@@ -325,8 +320,8 @@ test_expect_success 'shortlog for two branches' '
 '
 
 test_expect_success 'merge-msg -F' '
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
@@ -335,8 +330,8 @@ test_expect_success 'merge-msg -F' '
 '
 
 test_expect_success 'merge-msg -F in subdirectory' '
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 	git checkout master &&
 	test_tick &&
 	git fetch . left right &&
@@ -350,8 +345,8 @@ test_expect_success 'merge-msg -F in subdirectory' '
 '
 
 test_expect_success 'merge-msg with nothing to merge' '
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 
 	>empty &&
 
@@ -376,8 +371,8 @@ test_expect_success 'merge-msg tag' '
 	  Common #1
 	EOF
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 
 	git checkout master &&
 	test_tick &&
@@ -406,8 +401,8 @@ test_expect_success 'merge-msg two tags' '
 	  Common #1
 	EOF
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 
 	git checkout master &&
 	test_tick &&
@@ -436,8 +431,8 @@ test_expect_success 'merge-msg tag and branch' '
 	  Common #1
 	EOF
 
-	test_might_fail git config --unset-all merge.log &&
-	git config merge.summary yes &&
+	test_unconfig merge.log &&
+	test_config merge.summary yes &&
 
 	git checkout master &&
 	test_tick &&
@@ -464,6 +459,8 @@ test_expect_success 'merge-msg lots of commits' '
 		echo "  ..."
 	} >expected &&
 
+	test_config merge.summary yes &&
+
 	git checkout master &&
 	test_tick &&
 	git fetch . long &&
@@ -472,4 +469,43 @@ test_expect_success 'merge-msg lots of commits' '
 	test_cmp expected actual
 '
 
+test_expect_success 'merge-msg with "merging" an annotated tag' '
+	test_config merge.log true &&
+
+	git checkout master^0 &&
+	git commit --allow-empty -m "One step ahead" &&
+	git tag -a -m "An annotated one" annote HEAD &&
+
+	git checkout master &&
+	git fetch . annote &&
+
+	git fmt-merge-msg <.git/FETCH_HEAD >actual &&
+	{
+		cat <<-\EOF
+		Merge tag '\''annote'\''
+
+		An annotated one
+
+		* tag '\''annote'\'':
+		  One step ahead
+		EOF
+	} >expected &&
+	test_cmp expected actual &&
+
+	test_when_finished "git reset --hard" &&
+	annote=$(git rev-parse annote) &&
+	git merge --no-commit $annote &&
+	{
+		cat <<-EOF
+		Merge tag '\''$annote'\''
+
+		An annotated one
+
+		* tag '\''$annote'\'':
+		  One step ahead
+		EOF
+	} >expected &&
+	test_cmp expected .git/MERGE_MSG
+'
+
 test_done