clone --dissociate: avoid locking pack files

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 #446

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

builtin/clone.c

@@ -1066,8 +1066,15 @@ 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();

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