From 6f99ef9c5283aee5befde99d3cfb10de98978d6b Mon Sep 17 00:00:00 2001
From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Fri, 8 Apr 2011 18:55:16 +0000
Subject: [PATCH] scripts/kconfig.pl: backport changes from trunk

git-svn-id: svn://svn.openwrt.org/openwrt/branches/backfire@26535 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
 scripts/kconfig.pl | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/kconfig.pl b/scripts/kconfig.pl
index 7073e3b1a..811327353 100755
--- a/scripts/kconfig.pl
+++ b/scripts/kconfig.pl
@@ -80,13 +80,15 @@ sub config_add($$$) {
 	return \%config;
 }
 
-sub config_diff($$) {
+sub config_diff($$$) {
 	my $cfg1 = shift;
 	my $cfg2 = shift;
+	my $new_only = shift;
 	my %config;
 	
 	foreach my $config (keys %$cfg2) {
 		if (!defined($cfg1->{$config}) or $cfg1->{$config} ne $cfg2->{$config}) {
+			next if $new_only and !defined($cfg1->{$config}) and $cfg2->{$config} eq '#undef';
 			$config{$config} = $cfg2->{$config};
 		}
 	}
@@ -146,7 +148,11 @@ sub parse_expr {
 	} elsif ($arg eq '>') {
 		my $arg1 = parse_expr($pos);
 		my $arg2 = parse_expr($pos);
-		return config_diff($arg1, $arg2);
+		return config_diff($arg1, $arg2, 0);
+	} elsif ($arg eq '>+') {
+		my $arg1 = parse_expr($pos);
+		my $arg2 = parse_expr($pos);
+		return config_diff($arg1, $arg2, 1);
 	} elsif ($arg eq '-') {
 		my $arg1 = parse_expr($pos);
 		my $arg2 = parse_expr($pos);