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?hp=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>
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