fast-import: Fix crash when referencing already existing objects

Commit a5c1780a0355a71b9fb70f1f1977ce726ee5b8d8 sets the pack_id of existing objects to MAX_PACK_ID. When the same object is referenced later again it is found in the local object hash. With such a pack_id fast-import should not try to locate that object in the newly created pack(s).

---
 fast-import.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

index 0ddf8fe..87eaada 100644
@@ -1013,7 +1013,7 @@ static void load_tree(struct tree_entry *root)
 		return;
 
 	myoe = find_object(sha1);
-	if (myoe) {
+	if (myoe && myoe->pack_id != MAX_PACK_ID) {
 		if (myoe->type != OBJ_TREE)
 			die("Not a tree: %s", sha1_to_hex(sha1));
 		t->delta_depth = 0;

1.5.2.24.g93d4

Thanks, that was a _really_ nasty bug. :-(

Turns out there's more cases. Such as if we reload a mark table of commits (--import-marks) and then try to create a branch from them. The existing commit will also have a pack_id of MAX_PACK_ID and we'll go right into the same corruption you saw and fixed here.

I will be pushing your two patches and my additional fixup to my maint branch tonight.

Shawn.