[PATCH] pre-commit sample hook: do not barf on the initial import

The example hook barfs on the initial import.  Ideally it should
produce a diff from an empty tree, but for now let's stop at
squelching the bogus error message.  Often an initial import
involves tons of badly formatted files from foreign SCM, so not
complaining about them like this patch does might actually be a
better idea than enforcing the "Perfect Patch" format on them.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 10 insertions, 3 deletions

diff --git a/templates/hooks--pre-commit b/templates/hooks--pre-commit
index 4bb6803b10..43d3b6ef4a 100644
--- a/templates/hooks--pre-commit
+++ b/templates/hooks--pre-commit
@@ -10,8 +10,16 @@
 # This is slightly modified from Andrew Morton's Perfect Patch.
 # Lines you introduce should not have trailing whitespace.
 # Also check for an indentation that has SP before a TAB.
+
+if git-rev-parse --verify HEAD 2>/dev/null
+then
+	git-diff-index -p -M --cached HEAD
+else
+	# NEEDSWORK: we should produce a diff with an empty tree here
+	# if we want to do the same verification for the initial import.
+	:
+fi |
 perl -e '
-    my $fh;
     my $found_bad = 0;
     my $filename;
     my $reported_filename = "";
@@ -31,8 +39,7 @@ perl -e '
 	print STDERR "* $why (line $lineno)\n";
 	print STDERR "$filename:$lineno:$line\n";
     }
-    open $fh, "-|", qw(git-diff-index -p -M --cached HEAD);
-    while (<$fh>) {
+    while (<>) {
 	if (m|^diff --git a/(.*) b/\1$|) {
 	    $filename = $1;
 	    next;