[PATCH] clone --dissociate: avoid locking pack files

[Johannes Schindelin <johannes.schindelin@gmx.de>]

When `git clone` is asked to dissociate the repository from the
reference repository whose objects were used, it is quite possible that
the pack files need to be repacked. In that case, the pack files need to
be deleted that were originally hard-links to the reference repository's
pack files.

On platforms where a file cannot be deleted if another process still
holds a handle on it, we therefore need to take pains to release all
pack files and indexes before dissociating.

This fixes https://github.com/git-for-windows/git/issues/446

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 builtin/clone.c            |  9 ++++++++-
 t/t5700-clone-reference.sh | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/builtin/clone.c b/builtin/clone.c
index 578da85..223adc4 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1064,8 +1064,15 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	transport_unlock_pack(transport);
 	transport_disconnect(transport);
 
-	if (option_dissociate)
+	if (option_dissociate) {
+		struct packed_git *p;
+
+		for (p = packed_git; p; p = p->next) {
+			close_pack_windows(p);
+			close_pack_index(p);
+		}
 		dissociate_from_references();
+	}
 
 	junk_mode = JUNK_LEAVE_REPO;
 	err = checkout();
diff --git a/t/t5700-clone-reference.sh b/t/t5700-clone-reference.sh
index ef1779f..2250ef4 100755
--- a/t/t5700-clone-reference.sh
+++ b/t/t5700-clone-reference.sh
@@ -188,5 +188,26 @@ test_expect_success 'clone and dissociate from reference' '
 	test_must_fail git -C R fsck &&
 	git -C S fsck
 '
+test_expect_success 'clone, dissociate from partial reference and repack' '
+	rm -fr P Q R &&
+	git init P &&
+	(
+		cd P &&
+		test_commit one &&
+		git repack &&
+		test_commit two &&
+		git repack
+	) &&
+	git clone --bare P Q &&
+	(
+		cd P &&
+		git checkout -b second &&
+		test_commit three &&
+		git repack
+	) &&
+	git clone --bare --dissociate --reference=P Q R &&
+	ls R/objects/pack/*.pack >packs.txt &&
+	test_line_count = 1 packs.txt
+'
 
 test_done
-- 
2.5.3.windows.1.3.gc322723