bundle create: keep symbolic refs' names instead of resolving them

When creating a bundle, symbolic refs used to be resolved to the
non-symbolic refs they point to before being written to the list
of contained refs.  I.e. "git bundle create a1.bundle HEAD master"
would show something like

388afe7881b33102fada216dd07806728773c011        refs/heads/master
388afe7881b33102fada216dd07806728773c011        refs/heads/master

instead of

388afe7881b33102fada216dd07806728773c011        HEAD
388afe7881b33102fada216dd07806728773c011        refs/heads/master

Introduce a special handling so that the symbolic refs are listed
with the names passed on the command line.

Noticed by Santi Béjar.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-bundle.c

@@ -6,6 +6,7 @@
 #include "revision.h"
 #include "list-objects.h"
 #include "run-command.h"
+#include "refs.h"
 
 /*
  * Basic handler for bundle files to connect repositories via sneakernet.
@@ -253,11 +254,17 @@ static int create_bundle(struct bundle_header *header, const char *path,
 		struct object_array_entry *e = revs.pending.objects + i;
 		unsigned char sha1[20];
 		char *ref;
+		const char *display_ref;
+		int flag;
 
 		if (e->item->flags & UNINTERESTING)
 			continue;
 		if (dwim_ref(e->name, strlen(e->name), sha1, &ref) != 1)
 			continue;
+		if (!resolve_ref(e->name, sha1, 1, &flag))
+			flag = 0;
+		display_ref = (flag & REF_ISSYMREF) ? e->name : ref;
+
 		/*
 		 * Make sure the refs we wrote out is correct; --max-count and
 		 * other limiting options could have prevented all the tips
@@ -308,7 +315,7 @@ static int create_bundle(struct bundle_header *header, const char *path,
 		ref_count++;
 		write_or_die(bundle_fd, sha1_to_hex(e->item->sha1), 40);
 		write_or_die(bundle_fd, " ", 1);
-		write_or_die(bundle_fd, ref, strlen(ref));
+		write_or_die(bundle_fd, display_ref, strlen(display_ref));
 		write_or_die(bundle_fd, "\n", 1);
 		free(ref);
 	}

t/t5510-fetch.sh

@@ -153,4 +153,17 @@ test_expect_success 'bundle should be able to create a full history' '
 
 '
 
+test_expect_success 'bundle should record HEAD correctly' '
+
+	cd "$D" &&
+	git bundle create bundle5 HEAD master &&
+	git bundle list-heads bundle5 >actual &&
+	for h in HEAD refs/heads/master
+	do
+		echo "$(git rev-parse --verify $h) $h"
+	done >expect &&
+	diff -u expect actual
+
+'
+
 test_done