Dpkg.pm: Make regex for $progname more robust

While it is not very common to have $0 contain no
'/', it may happen on occasion (after all it happened to
me ;).

ChangeLog

@@ -1,3 +1,8 @@
+2007-09-20  Frank Lichtenheld  <djpig@debian.org>
+
+	* scripts/Dpkg.pm: Make the regex for determining
+	$progname more robust.
+
 2007-09-18  Guillem Jover  <guillem@debian.org>
 
 	* lib/mlib.c (checksubprocerr): Warn instead of erroring out in case

scripts/Dpkg.pm

@@ -6,7 +6,7 @@ use warnings;
 use base qw(Exporter);
 our @EXPORT = qw($version $progname $admindir $dpkglibdir $pkgdatadir);
 
-our ($progname) = $0 =~ m:.*/(.*):;
+our ($progname) = $0 =~ m#(?:.*/)?([^/]*)#;
 
 # The following lines are automatically fixed at install time
 our $version = "1.14";