A possible segfault was introduced in c08830de41 (mv: check if
<destination> is a SKIP_WORKTREE_DIR, 2022-08-09).
When running t7001 with SANITIZE=address, problem appears when running:
git mv path1/path2/ .
or
git mv directory ../
or
any <destination> that makes dest_path[0] an empty string.
The add_slash() call could segfault when path argument to it is an empty
string, because it makes an out-of-bounds read to decide if an extra
slash '/' needs to be appended to it.
As add_slash() is used to make sure that a valid pathname to a file in
the given directory can be made by appending a filename after the value
returned from it, if path is an empty string, we want to return it
as-is. The path to a file "F" in the top-level of the working tree
(i.e. path=="") is formed by appending "F" after "" (i.e. path) without
any slash in between.
So, just like the case where a non-empty path already ends with a slash,
return an empty path as-is.
Reported-by: Jeff King <peff@peff.net>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
7ead46810b