installdb,cli/listinstalled: Thinko fix

The build host should be an empty string for old packages.
"pisi li -b ''" now returns old packages, too.

pisi/cli/listinstalled.py

@@ -41,7 +41,7 @@ Usage: list-installed
 
         group.add_option("-b", "--with-build-host",
                          action="store",
-                         default="localhost",
+                         default=None,
                          help=_("Only list the installed packages built "
                                 "by the given host"))
         group.add_option("-l", "--long", action="store_true",
@@ -57,7 +57,7 @@ Usage: list-installed
         self.init(database = True, write = False)
 
         build_host = ctx.get_option("with_build_host")
-        if not build_host:
+        if build_host is None:
             installed = self.installdb.list_installed()
         else:
             installed = self.installdb.list_installed_with_build_host(build_host)

pisi/db/installdb.py

@@ -118,13 +118,19 @@ class InstallDB(lazydb.LazyDB):
         return self.installed_db.has_key(package)
 
     def list_installed_with_build_host(self, build_host):
-        xml_line = "<BuildHost>%s</BuildHost>" % re.escape(build_host)
-        build_host_re = re.compile(xml_line)
+        build_host_re = re.compile("<BuildHost>(.*?)</BuildHost>")
         found = []
         for name in self.list_installed():
             xml = open(os.path.join(self.package_path(name), ctx.const.metadata_xml)).read()
-            if build_host_re.search(xml):
-                found.append(name)
+            matched = build_host_re.search(xml)
+            if matched:
+                if build_host != matched.groups()[0]:
+                    continue
+            elif build_host:
+                continue
+
+            found.append(name)
+
         return found
 
     def __get_version(self, meta_doc):