git-clone -s: document problems with git gc --prune

There is a scenario when using git clone -s and git gc --prune togother is
dangerous. Document this.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index fdccbd4cbe8fcb336b412d75dc070a5d7b5acb1e..23418816146d0b65eeabdd7a3d67dcd7e8c760e1 100644 (file)
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -62,6 +62,14 @@ OPTIONS
        .git/objects/info/alternates to share the objects
        with the source repository.  The resulting repository
        starts out without any object of its own.
+       *NOTE*: this is a possibly dangerous operation; do *not* use
+       it unless you understand what it does. If you clone your
+       repository using this option, then delete branches in the
+       source repository and then run linkgit:git-gc[1] using the
+       '--prune' option in the source repository, it may remove
+       objects which are referenced by the cloned repository.
+
+
 
 --reference <repository>::
        If the reference repository is on the local machine