Dpkg::Deps::parse(): handle empty fields properly instead of returning undef

And revert previous changes made to dpkg-gencontrol to skip empty fields.

ChangeLog

@@ -7,7 +7,8 @@
 	problem (when a RPATH contains $ORIGIN and when the value of
 	this variable can't be determined because we don't know what
 	is the root directory of the temporary tree).
-	* scripts/dpkg-gencontrol.pl: Don't try to parse empty fields.
+	* scripts/Dpkg/Deps.pm: Fix parse() to handle empty fields instead
+	of returning undef.
 
 2007-11-19  Guillem Jover  <guillem@debian.org>
 

debian/changelog

@@ -2,8 +2,8 @@ dpkg (1.14.9) UNRELEASED; urgency=low
 
   [ Raphael Hertzog ]
   * Fix bad behaviour of Dpkg::Path::get_pkg_root_dir() and adjust
-    dpkg-shlibdeps accordingly.
-  * Fix dpkg-gencontrol to not try to parse and simplify empty fields.
+    dpkg-shlibdeps accordingly. Closes: #452012
+  * Fix Dpkg::Deps to accept empty fields. Closes: #452013
 
   [ Updated man pages translations ]
     * German (Helge Kreutzmann).

scripts/Dpkg/Deps.pm

@@ -321,7 +321,6 @@ sub parse {
 	    push @dep_list, $dep_or;
 	}
     }
-    return undef if not @dep_list;
     my $dep_and;
     if ($options{union}) {
 	$dep_and = Dpkg::Deps::Union->new();

scripts/dpkg-gencontrol.pl

@@ -249,19 +249,20 @@ if (exists $fi{"C$myindex Provides"}) {
 my (@seen_deps);
 foreach my $field (@pkg_dep_fields) {
     my $key = "C$myindex $field";
-    if (exists $fi{$key} and $fi{$key}) {
+    if (exists $fi{$key}) {
 	my $dep;
+	my $field_value = substvars($fi{$key});
 	if ($dep_field_type{$field} eq 'normal') {
-	    $dep = Dpkg::Deps::parse(substvars($fi{$key}), use_arch => 1,
+	    $dep = Dpkg::Deps::parse($field_value, use_arch => 1,
                                      reduce_arch => 1);
-	    error(_g("error occurred while parsing %s"), $_) unless defined $dep;
+	    error(_g("error occurred while parsing %s"), $field_value) unless defined $dep;
 	    $dep->simplify_deps($facts, @seen_deps);
 	    # Remember normal deps to simplify even further weaker deps
 	    push @seen_deps, $dep if $dep_field_type{$field} eq 'normal';
 	} else {
-	    $dep = Dpkg::Deps::parse(substvars($fi{$key}), use_arch => 1,
+	    $dep = Dpkg::Deps::parse($field_value, use_arch => 1,
                                      reduce_arch => 1, union => 1);
-	    error(_g("error occurred while parsing %s"), $_) unless defined $dep;
+	    error(_g("error occurred while parsing %s"), $field_value) unless defined $dep;
 	    $dep->simplify_deps($facts);
 	}
 	$dep->sort();