From 10a49587fabde88c0afbc80a99d97fae91811f5f Mon Sep 17 00:00:00 2001
From: "David A. Greene" <greened@obbligato.org>
Date: Mon, 4 Feb 2013 22:06:03 -0600
Subject: contrib/subtree: better error handling for 'subtree add'

Check refspecs for validity before passing them on to other commands.
This lets us generate more helpful error messages.

Signed-off-by: David A. Greene <greened@obbligato.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
index 5598210..771f39d 100755
--- a/contrib/subtree/git-subtree.sh
+++ b/contrib/subtree/git-subtree.sh
@@ -497,12 +497,18 @@ cmd_add()
 	ensure_clean
 	
 	if [ $# -eq 1 ]; then
-		"cmd_add_commit" "$@"
+	    git rev-parse -q --verify "$1^{commit}" >/dev/null ||
+	    die "'$1' does not refer to a commit"
+
+	    "cmd_add_commit" "$@"
 	elif [ $# -eq 2 ]; then
-		"cmd_add_repository" "$@"
+	    git rev-parse -q --verify "$2^{commit}" >/dev/null ||
+	    die "'$2' does not refer to a commit"
+
+	    "cmd_add_repository" "$@"
 	else
 	    say "error: parameters were '$@'"
-	    die "Provide either a refspec or a repository and refspec."
+	    die "Provide either a commit or a repository and commit."
 	fi
 }
 
-- 
cgit v0.10.2-6-g49f6