dpkg-source: fix ignore regexp for source format 1.0 when -i is not used

The variable is defined by default but empty and the check was wrong
leading all files to be ignored.

debian/changelog

@@ -1,3 +1,11 @@
+dpkg (1.15.7.1) UNRELEASED; urgency=low
+
+  * Fix dpkg-source -b (without -i) for source packages 1.0. Closes: #578693
+    It was erroneously ignoring all changes because the ignore regex was
+    wrong (due to the change to ignore debian/source/local-options).
+
+ -- Raphaël Hertzog <hertzog@debian.org>  Thu, 22 Apr 2010 07:50:04 +0200
+
 dpkg (1.15.7) unstable; urgency=low
 
   [ Raphaël Hertzog ]

scripts/Dpkg/Source/Package/V1.pm

@@ -43,7 +43,7 @@ sub init_options {
     my ($self) = @_;
     # Don't call $self->SUPER::init_options() on purpose, V1.0 has no
     # ignore by default
-    if (defined $self->{'options'}{'diff_ignore_regexp'}) {
+    if ($self->{'options'}{'diff_ignore_regexp'}) {
 	$self->{'options'}{'diff_ignore_regexp'} .= '|(?:^|/)debian/source/local-options$';
     } else {
 	$self->{'options'}{'diff_ignore_regexp'} = '(?:^|/)debian/source/local-options$';