Merge branch 'dl/zero-oid-in-hooks'

Adjust sample hooks for hash algorithm other than SHA-1.

* dl/zero-oid-in-hooks:
  hooks--update.sample: use hash-agnostic zero OID
  hooks--pre-push.sample: use hash-agnostic zero OID
  hooks--pre-push.sample: modernize script

templates/hooks--pre-push.sample

@@ -14,7 +14,7 @@
 # Information about the commits which are being pushed is supplied as lines to
 # the standard input in the form:
 #
-#   <local ref> <local sha1> <remote ref> <remote sha1>
+#   <local ref> <local oid> <remote ref> <remote oid>
 #
 # This sample shows how to prevent push of commits where the log message starts
 # with "WIP" (work in progress).
@@ -22,27 +22,27 @@
 remote="$1"
 url="$2"
 
-z40=0000000000000000000000000000000000000000
+zero=$(git hash-object --stdin </dev/null | tr '[0-9a-f]' '0')
 
-while read local_ref local_sha remote_ref remote_sha
+while read local_ref local_oid remote_ref remote_oid
 do
-	if [ "$local_sha" = $z40 ]
+	if test "$local_oid" = "$zero"
 	then
 		# Handle delete
 		:
 	else
-		if [ "$remote_sha" = $z40 ]
+		if test "$remote_oid" = "$zero"
 		then
 			# New branch, examine all commits
-			range="$local_sha"
+			range="$local_oid"
 		else
 			# Update to existing branch, examine new commits
-			range="$remote_sha..$local_sha"
+			range="$remote_oid..$local_oid"
 		fi
 
 		# Check for WIP commit
-		commit=`git rev-list -n 1 --grep '^WIP' "$range"`
-		if [ -n "$commit" ]
+		commit=$(git rev-list -n 1 --grep '^WIP' "$range")
+		if test -n "$commit"
 		then
 			echo >&2 "Found WIP commit in $local_ref, not pushing"
 			exit 1

templates/hooks--update.sample

@@ -60,7 +60,7 @@ esac
 
 # --- Check types
 # if $newrev is 0000...0000, it's a commit to delete a ref.
-zero="0000000000000000000000000000000000000000"
+zero=$(git hash-object --stdin </dev/null | tr '[0-9a-f]' '0')
 if [ "$newrev" = "$zero" ]; then
 	newrev_type=delete
 else