[PATCH 5/5] setup_revisions: remember whether a ref was positive or not

[Sverre Rabbelier <srabbelier@gmail.com>]

From: Johannes Schindelin <Johannes.Schindelin@gmx.de>

This will be required by fast-export, when no commits were
exported, but the refs should be set, of course.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
---

  And then finally, the fix. Thanks for reading.

 builtin/fast-export.c  |   36 +++++++++++++++++++++++++++++++-----
 t/t9350-fast-export.sh |    2 +-
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index 628eab0..9c24f4e 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -17,6 +17,8 @@
 #include "utf8.h"
 #include "parse-options.h"
 
+#define REF_HANDLED (ALL_REV_FLAGS + 1)
+
 static const char *fast_export_usage[] = {
 	"git fast-export [rev-list-opts]",
 	NULL
@@ -456,6 +458,7 @@ static void handle_tag(const char *name, struct tag *tag)
 }
 
 static void get_tags_and_duplicates(struct object_array *pending,
+				    struct string_list *refs,
 				    struct string_list *extra_refs)
 {
 	struct tag *tag;
@@ -507,8 +510,11 @@ static void get_tags_and_duplicates(struct object_array *pending,
 		if (commit->util)
 			/* more than one name for the same object */
 			string_list_append(extra_refs, full_name)->util = commit;
-		else
+		else {
 			commit->util = full_name;
+			/* we might need to set this ref explicitly */
+			string_list_append(refs, full_name)->util = commit;
+		}
 	}
 }
 
@@ -524,10 +530,29 @@ static void handle_reset(const char *name, struct object *object)
 		       sha1_to_hex(object->sha1));
 }
 
-static void handle_tags_and_duplicates(struct string_list *extra_refs)
+static void handle_tags_and_duplicates(struct string_list *refs, struct string_list *extra_refs)
 {
 	int i;
 
+	/* even if no commits were exported, we need to export the ref */
+	for (i = refs->nr - 1; i >= 0; i--) {
+		const char *name = refs->items[i].string;
+		struct object *object = refs->items[i].util;
+
+		if (!(object->flags & REF_HANDLED)) {
+			if (object->type & OBJ_TAG)
+				handle_tag(name, (struct tag *)object);
+			else {
+				if (!prefixcmp(name, "refs/tags/") &&
+				    (tag_of_filtered_mode != REWRITE ||
+				     !get_object_mark(object)))
+					continue;
+				handle_reset(name, object);
+				object->flags |= REF_HANDLED;
+			}
+		}
+	}
+
 	for (i = extra_refs->nr - 1; i >= 0; i--) {
 		const char *name = extra_refs->items[i].string;
 		struct object *object = extra_refs->items[i].util;
@@ -617,7 +642,7 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
 	struct object_array commits = OBJECT_ARRAY_INIT;
-	struct string_list extra_refs = STRING_LIST_INIT_NODUP;
+	struct string_list refs = STRING_LIST_INIT_NODUP, extra_refs = STRING_LIST_INIT_NODUP;
 	struct commit *commit;
 	char *export_filename = NULL, *import_filename = NULL;
 	struct option options[] = {
@@ -669,7 +694,7 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
 	if (import_filename && revs.prune_data.nr)
 		full_tree = 1;
 
-	get_tags_and_duplicates(&revs.pending, &extra_refs);
+	get_tags_and_duplicates(&revs.pending, &refs, &extra_refs);
 
 	if (prepare_revision_walk(&revs))
 		die("revision walk setup failed");
@@ -681,11 +706,12 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
 		}
 		else {
 			handle_commit(commit, &revs);
+			commit->object.flags |= REF_HANDLED;
 			handle_tail(&commits, &revs);
 		}
 	}
 
-	handle_tags_and_duplicates(&extra_refs);
+	handle_tags_and_duplicates(&refs, &extra_refs);
 
 	if (export_filename)
 		export_marks(export_filename);
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index ed0417a..d2d7ef8 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -420,7 +420,7 @@ from $(git rev-parse master)
 
 EOF
 
-test_expect_failure 'refs are updated even if no commits need to be exported' '
+test_expect_success 'refs are updated even if no commits need to be exported' '
 	git fast-export master..master > actual &&
 	test_cmp expected actual
 '
-- 
1.7.6.385.g91185.dirty