From: Junio C Hamano <junkio@cox.net>
Date: Mon, 24 Apr 2006 22:12:42 +0000 (-0700)
Subject: cache-tree: protect against "git prune".
X-Git-Tag: v1.4.0-rc1~45^2~21
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/dd0c34c46bdda0c20fd92d00516e711a4c9f7837

cache-tree: protect against "git prune".

We reused the cache-tree data without verifying the tree object
still exists.  Recompute in cache_tree_update() an otherwise
valid cache-tree entry when the tree object disappeared.

This is not usually a problem, but theoretically without this
fix things can break when the user does something like this:

- read-index from a side branch
- write-tree the result
- remove the side branch with "git branch -D"
- remove the unreachable objects with "git prune"
- write-tree what is in the index.

Signed-off-by: Junio C Hamano <junkio@cox.net>
---

diff --git a/cache-tree.c b/cache-tree.c
index f6d1dd1d7f..b34b0bc317 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -177,7 +177,7 @@ static int update_one(struct cache_tree *it,
 	char *buffer;
 	int i;
 
-	if (0 <= it->entry_count)
+	if (0 <= it->entry_count && has_sha1_file(it->sha1))
 		return it->entry_count;
 
 	/*