[PATCH v2 41/42] add--interactive: compute the empty tree value

[brian m. carlson]

The interactive add script hard-codes the object ID of the empty tree.
To avoid any problems when changing hashes, compute this value when used
and cache it for any future uses.

Signed-off-by: brian m. carlson <sand...@crustytoothpaste.net>
---
 git-add--interactive.perl | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index c1f52e457f..36f38ced90 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -205,8 +205,15 @@ my $status_head = sprintf($status_fmt, __('staged'), 
__('unstaged'), __('path'))
        }
 }
 
-sub get_empty_tree {
-       return '4b825dc642cb6eb9a060e54bf8d69288fbee4904';
+{
+       my $empty_tree;
+       sub get_empty_tree {
+               return $empty_tree if defined $empty_tree;
+
+               $empty_tree = run_cmd_pipe(qw(git hash-object -t tree 
/dev/null));
+               chomp $empty_tree;
+               return $empty_tree;
+       }
 }
 
 sub get_diff_reference {