Don't diff empty tree on branch creation in paranoid update hook

Listing all files in a branch during branch creation is silly;
the user's file-level ACLs probably don't mean anything at this
point.  We now treat the base case of 0{40} as an empty diff,
as this happens only when the user is creating the branch and
there are file level ACLs that diff against the old value of
the branch.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/hooks/update-paranoid b/contrib/hooks/update-paranoid
index 068fa3708331bbb7d451040715c8bba9623f8c7e..6e0d97c89facd69db8b01ebdaf09f3cca5e1a28e 100644 (file)
--- a/contrib/hooks/update-paranoid
+++ b/contrib/hooks/update-paranoid
@@ -225,14 +225,12 @@ sub load_diff ($) {
                local $/ = "\0";
                my %this_diff;
                if ($base =~ /^0{40}$/) {
-                       open(T,'-|','git','ls-tree',
-                               '-r','--name-only','-z',
-                               $new) or return undef;
-                       while (<T>) {
-                               chop;
-                               $this_diff{$_} = 'A';
-                       }
-                       close T or return undef;
+                       # Don't load the diff at all; we are making the
+                       # branch and have no base to compare to in this
+                       # case.  A file level ACL makes no sense in this
+                       # context.  Having an empty diff will allow the
+                       # branch creation.
+                       #
                } else {
                        open(T,'-|','git','diff-tree',
                                '-r','--name-status','-z',