[PATCHv3 2/7] fast-export: Omit tags that tag trees

[newren@gmail.com]

From: Elijah Newren <newren@gmail.com>

Commit c0582c53bcf4e83bba70e1ad23abbad31f96ebc8 introduced logic to just
omit tags that point to tree objects.  However, these objects were still
being output and were pointing at "mark :0", which caused fast-import to
crash.  This patch makes sure such tags (including deeper nestings such
as tags of tags of trees), are omitted.

Signed-off-by: Elijah Newren <newren@gmail.com>
---
Since the last series, the code has been moved to the handle_tag
function, as suggested by Junio.  Also, it now correctly catches and
omits tags of tags of trees, tags of tags of tags of trees, etc.

 builtin-fast-export.c  |   15 +++++++++++++++
 t/t9301-fast-export.sh |    8 +++++++-
 2 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/builtin-fast-export.c b/builtin-fast-export.c
index e0cfa60..8c90a2d 100644
--- a/builtin-fast-export.c
+++ b/builtin-fast-export.c
@@ -289,6 +289,21 @@ static void handle_tag(const char *name, struct tag *tag)
 	char *buf;
 	const char *tagger, *tagger_end, *message;
 	size_t message_size = 0;
+	struct object *tagged;
+
+	/* Trees have no identifer in fast-export output, thus we have no way
+	 * to output tags of trees, tags of tags of trees, etc.  Simply omit
+	 * such tags.
+	 */
+	tagged = tag->tagged;
+	while (tagged->type == OBJ_TAG) {
+		tagged = ((struct tag *)tagged)->tagged;
+	}
+	if (tagged->type == OBJ_TREE) {
+		warning("Omitting tag %s,\nsince tags of trees (or tags of tags of trees, etc.) are not supported.",
+			sha1_to_hex(tag->object.sha1));
+		return;
+	}
 
 	buf = read_sha1_file(tag->object.sha1, &type, &size);
 	if (!buf)
diff --git a/t/t9301-fast-export.sh b/t/t9301-fast-export.sh
index 8c8a9e6..3f13e6b 100755
--- a/t/t9301-fast-export.sh
+++ b/t/t9301-fast-export.sh
@@ -271,8 +271,14 @@ test_expect_success 'set-up a few more tags for tag export tests' '
 	git tag -a tag-obj_tag-obj -m "tagging a tag" tree_tag-obj
 '
 
+test_expect_success 'tree_tag'        '
+	mkdir result &&
+	(cd result && git init) &&
+	git fast-export tree_tag > fe-stream &&
+	(cd result && git fast-import < ../fe-stream)
+'
+
 # NEEDSWORK: not just check return status, but validate the output
-test_expect_success 'tree_tag'        'git fast-export tree_tag'
 test_expect_success 'tree_tag-obj'    'git fast-export tree_tag-obj'
 test_expect_success 'tag-obj_tag'     'git fast-export tag-obj_tag'
 test_expect_success 'tag-obj_tag-obj' 'git fast-export tag-obj_tag-obj'
-- 
1.6.3.2.323.geb889