Update shell scripts to compute empty tree object ID

diff --git a/templates/hooks--pre-commit.sample b/templates/hooks--pre-commit.sample
index 68d62d5446d963dc69006ad9a83907c6690f92c1..6a756416384c210ada2631f17862f5c01fffa478 100755 (executable)
--- a/templates/hooks--pre-commit.sample
+++ b/templates/hooks--pre-commit.sample
@@ -12,7 +12,7 @@ then
        against=HEAD
 else
        # Initial commit: diff against an empty tree object
-       against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
+       against=$(git hash-object -t tree /dev/null)
 fi
 
 # If you want to allow non-ASCII filenames set this variable to true.