Merge lp:~mvo/ubuntu-release-upgrader/use-str.format into lp:ubuntu-release-upgrader

[Michael Vogt]

Use str.format() with gettext (eventually everywhere) to avoid crashes if e.g. incorrect translations are specified. The worst case with str.format() is that the information is not displayed correctly, but it won't crash like e.g. LP: #1311396

[Michael Terry (mterry)]

Maybe str.format is better for other reasons, but you can certainly still get tracebacks from it:

$ python3 -c "'hello {0'.format('world')"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: expected '}' before end of string

[Michael Vogt (mvo)]

Hi Michael, thanks for your comment. Indeed, I should have been more clear.

The issue that is fixed is:

$ python -c 'print("foo" % "bar")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
TypeError: not all arguments converted during string formatting

$ python -c 'print("foo".format("bar"))'
foo

But yes, if a translation has a incorrect number of {} it will still crash, so maybe its not worth
doing all the work and instead use the "Foo %(bar)s" % { "bar": "some-str" } approach where its
also ok to leave out a argument. I.e.
$ python -c 'print("foo" % {"bar": "bar"})'
foo

[Barry Warsaw (barry)]

It might be a lot of work to port, but I will suggest using my flufl.i18n package, which has a lot of nice convenience APIs and safeguards for doing i18n interpolation.

http://pythonhosted.org/flufl.i18n/docs/using.html

And of course, it's packaged up :).

[Barry Warsaw (barry)]

Also note that with modern Pythons

'{0}'.format('foo')

is equivalent to

'{}'.format('foo')

Unmerged revisions

2779. By Michael Vogt on 2014-04-24

replace all %s style format with str.format() in gettext to be more robust against crashes from incorrectly formated translations

2778. By Michael Vogt on 2014-04-24

use str.format() for all ngettext() to avoid crashes on incorrect number of parameters (LP: #1311396

=== modified file 'DistUpgrade/DistUpgradeAptCdrom.py'
--- DistUpgrade/DistUpgradeAptCdrom.py	2012-06-12 13:52:04 +0000
+++ DistUpgrade/DistUpgradeAptCdrom.py	2014-04-24 08:46:39 +0000
@@ -295,7 +295,7 @@
                              _("There was a error adding the CD, the "
                                "upgrade will abort. Please report this as "
                                "a bug if this is a valid Ubuntu CD.\n\n"
-                               "The error message was:\n'%s'") % e)
+                               "The error message was:\n'{0}'").format(e))
             return False
         logging.debug("AptCdrom.add() returned: %s" % res)
         return res
 
=== modified file 'DistUpgrade/DistUpgradeCache.py'
--- DistUpgrade/DistUpgradeCache.py	2014-04-15 08:57:53 +0000
+++ DistUpgrade/DistUpgradeCache.py	2014-04-24 08:46:39 +0000
@@ -152,17 +152,17 @@
             header = ngettext("Remove package in bad state",
                               "Remove packages in bad state",
                               len(reqreinst))
-            summary = ngettext("The package '%s' is in an inconsistent "
+            summary = ngettext("The package '{0}' is in an inconsistent "
                                "state and needs to be reinstalled, but "
                                "no archive can be found for it. "
                                "Do you want to remove this package "
                                "now to continue?",
-                               "The packages '%s' are in an inconsistent "
+                               "The packages '{0}' are in an inconsistent "
                                "state and need to be reinstalled, but "
                                "no archives can be found for them. Do you "
                                "want to remove these packages now to "
                                "continue?",
-                               len(reqreinst)) % ", ".join(reqreinst)
+                               len(reqreinst)).format(", ".join(reqreinst))
             if view.askYesNoQuestion(header, summary):
                 self.release_lock()
                 cmd = ["/usr/bin/dpkg", "--remove", "--force-remove-reinstreq"] + list(reqreinst)
@@ -727,13 +727,13 @@
         for pkg in self.get_changes():
             if pkg.marked_delete and self._inRemovalBlacklist(pkg.name):
                 logging.debug("The package '%s' is marked for removal but it's in the removal blacklist", pkg.name)
-                raise SystemError(_("The package '%s' is marked for removal but it is in the removal blacklist.") % pkg.name)
+                raise SystemError(_("The package '{0}' is marked for removal but it is in the removal blacklist.").format(pkg.name))
             if pkg.marked_delete and (
                     pkg._pkg.essential == True and
                     pkg.installed.architecture == main_arch and
                     not pkg.name in removeEssentialOk):
                 logging.debug("The package '%s' is marked for removal but it's an ESSENTIAL package", pkg.name)
-                raise SystemError(_("The essential package '%s' is marked for removal.") % pkg.name)
+                raise SystemError(_("The essential package '{0}' is marked for removal.").format(pkg.name))
         # check bad-versions blacklist
         badVersions = self.config.getlist("Distro", "BadVersions")
         for bv in badVersions:
@@ -742,7 +742,7 @@
                 self[pkgname].candidate.version == ver and
                 (self[pkgname].marked_install or
                  self[pkgname].marked_upgrade)):
-                raise SystemError(_("Trying to install blacklisted version '%s'") % bv)
+                raise SystemError(_("Trying to install blacklisted version '{0}'").format(bv))
         return True
 
     def _lookupPkgRecord(self, pkg):
@@ -861,7 +861,7 @@
                     except (SystemError, KeyError) as e:
                         logging.error("failed to mark '%s' for install (%s)" %
                                       (key, e))
-                        view.error(_("Can't install '%s'") % key,
+                        view.error(_("Can't install '{0}'").format(key),
                                    _("It was impossible to install a "
                                      "required package. Please report "
                                      "this as a bug using "
@@ -875,13 +875,13 @@
             meta_pkgs = ', '.join(metapkgs[0:-1])
             view.error(_("Can't guess meta-package"),
                        _("Your system does not contain a "
-                         "%s or %s package and it was not "
+                         "{0} or {1} package and it was not "
                          "possible to detect which version of "
                          "Ubuntu you are running.\n "
                          "Please install one of the packages "
                          "above first using synaptic or "
-                         "apt-get before proceeding.") %
-                        (meta_pkgs, metapkgs[-1]))
+                         "apt-get before proceeding.").format(
+                             meta_pkgs, metapkgs[-1]))
             return False
         return True
 
 
=== modified file 'DistUpgrade/DistUpgradeController.py'
--- DistUpgrade/DistUpgradeController.py	2014-04-11 22:30:39 +0000
+++ DistUpgrade/DistUpgradeController.py	2014-04-24 08:46:39 +0000
@@ -307,8 +307,8 @@
                   "over ssh currently because in case of failure "
                   "it is harder to recover.\n\n"
                   "If you continue, an additional ssh daemon will be "
-                  "started at port '%s'.\n"
-                  "Do you want to continue?") % port)
+                  "started at port '{0}'.\n"
+                  "Do you want to continue?").format(port))
             # abort
             if res == False:
                 sys.exit(1)
@@ -318,10 +318,10 @@
             if res == 0:
                 summary = _("Starting additional sshd")
                 descr =  _("To make recovery in case of failure easier, an "
-                           "additional sshd will be started on port '%s'. "
+                           "additional sshd will be started on port '{0}'. "
                            "If anything goes wrong with the running ssh "
                            "you can still connect to the additional one.\n"
-                           ) % port
+                           ).format(port)
                 if iptables_active():
                     cmd = "iptables -I INPUT -p tcp --dport %s -j ACCEPT" % port
                     descr += _(
@@ -398,8 +398,9 @@
         if not (release == self.fromDist or release == self.toDist):
             logging.error("Bad upgrade: '%s' != '%s' " % (release, self.fromDist))
             self._view.error(_("Can not upgrade"),
-                             _("An upgrade from '%s' to '%s' is not "
-                               "supported with this tool." % (release, self.toDist)))
+                             _("An upgrade from '{0}' to '{1}' is not "
+                               "supported with this tool.").format(
+                                   release, self.toDist))
             sys.exit(1)
 
         # setup aufs
@@ -417,11 +418,11 @@
             self._view.information(_("Sandbox mode"),
                                    _("This upgrade is running in sandbox "
                                      "(test) mode. All changes are written "
-                                     "to '%s' and will be lost on the next "
+                                     "to '{0}' and will be lost on the next "
                                      "reboot.\n\n"
                                      "*No* changes written to a system directory "
                                      "from now until the next reboot are "
-                                     "permanent.") % aufs_rw_dir)
+                                     "permanent.").format(aufs_rw_dir))
 
         # setup backports (if we have them)
         if self.options and self.options.havePrerequists:
@@ -482,12 +483,12 @@
             if os.path.exists(systemdir) and not os.access(systemdir, os.W_OK):
                 logging.error("%s not writable" % systemdir)
                 self._view.error(
-                    _("Can not write to '%s'") % systemdir,
+                    _("Can not write to '{0}'").format(systemdir),
                     _("Its not possible to write to the system directory "
-                      "'%s' on your system. The upgrade can not "
+                      "'{0}' on your system. The upgrade can not "
                       "continue.\n"
                       "Please make sure that the system directory is "
-                      "writable.") % systemdir)
+                      "writable.").format(systemdir))
                 self.abort()
             
 
@@ -640,7 +641,7 @@
                 "%s-proposed" % self.fromDist in entry.dist):
                 logging.debug("upgrade to development release, disabling proposed")
                 entry.dist = "%s-proposed" % self.toDist
-                entry.comment += _("Not for humans during development stage of release %s") % self.toDist
+                entry.comment += _("Not for humans during development stage of release {0}").format(self.toDist)
                 entry.disabled = True
                 continue
 
@@ -726,7 +727,7 @@
                 # disable anything that is not from a official mirror or a whitelisted third party
                 if entry.dist == self.fromDist:
                     entry.dist = self.toDist
-                disable_comment = " " + _("disabled on upgrade to %s") % self.toDist
+                disable_comment = " " + _("disabled on upgrade to {0}").format(self.toDist)
                 if isinstance(entry.comment, bytes):
                     entry.comment += disable_comment.encode('UTF-8')
                 else:
@@ -770,10 +771,10 @@
                                "out of date.\n\n"
                                "Do you want to rewrite your "
                                "'sources.list' file anyway? If you choose "
-                               "'Yes' here it will update all '%s' to '%s' "
+                               "'Yes' here it will update all '{0}' to '{1}' "
                                "entries.\n"
                                "If you select 'No' the upgrade will cancel."
-                               ) % (self.fromDist, self.toDist))
+                               ).format(self.fromDist, self.toDist))
             if res:
                 # re-init the sources and try again
                 self.sources = SourcesList(matcherPath=".")
@@ -784,10 +785,10 @@
                     #hm, still nothing useful ...
                     prim = _("Generate default sources?")
                     secon = _("After scanning your 'sources.list' no "
-                              "valid entry for '%s' was found.\n\n"
-                              "Should default entries for '%s' be "
+                              "valid entry for '{0}' was found.\n\n"
+                              "Should default entries for '{1}' be "
                               "added? If you select 'No', the upgrade "
-                              "will cancel.") % (self.fromDist, self.toDist)
+                              "will cancel.").format(self.fromDist, self.toDist)
                     if not self._view.askYesNoQuestion(prim, secon):
                         self.abort()
 
@@ -880,17 +881,17 @@
             header = ngettext("Package in inconsistent state",
                               "Packages in inconsistent state",
                               len(reqreinst))
-            summary = ngettext("The package '%s' is in an inconsistent "
+            summary = ngettext("The package '{0}' is in an inconsistent "
                                "state and needs to be reinstalled, but "
                                "no archive can be found for it. "
                                "Please reinstall the package manually "
                                "or remove it from the system.",
-                               "The packages '%s' are in an inconsistent "
+                               "The packages '{0}' are in an inconsistent "
                                "state and need to be reinstalled, but "
                                "no archive can be found for them. "
                                "Please reinstall the packages manually "
                                "or remove them from the system.",
-                               len(reqreinst)) % ", ".join(reqreinst)
+                               len(reqreinst)).format(", ".join(reqreinst))
             self._view.error(header, summary)
             return False
         # FIXME: check out what packages are downloadable etc to
@@ -899,8 +900,8 @@
         self.foreign_pkgs = self.cache._getForeignPkgs(self.origin, self.fromDist, self.toDist)
         if self.serverMode:
             self.tasks = self.cache.installedTasks
-        logging.debug("Foreign: %s" % " ".join(self.foreign_pkgs))
-        logging.debug("Obsolete: %s" % " ".join(self.obsolete_pkgs))
+        logging.debug("Foreign: {0}".format(" ".join(self.foreign_pkgs)))
+        logging.debug("Obsolete: {0}".format(" ".join(self.obsolete_pkgs)))
         return True
 
     def doUpdate(self, showErrors=True, forceRetries=None):
@@ -940,9 +941,10 @@
         " this checks if we have enough free space on /var and /usr"
         err_sum = _("Not enough free disk space")
         err_long= _("The upgrade has aborted. "
-                    "The upgrade needs a total of %s free space on disk '%s'. "
-                    "Please free at least an additional %s of disk "
-                    "space on '%s'. "
+                    "The upgrade needs a total of {0} free space on disk "
+                    "'{1}'. "
+                    "Please free at least an additional {2} of disk "
+                    "space on '{3}'. "
                     "Empty your trash and remove temporary "
                     "packages of former installations using "
                     "'sudo apt-get clean'.")
@@ -959,10 +961,10 @@
             # perspective, but it means we do not need to break the
             # string freeze
             for required in e.free_space_required_list:
-                self._view.error(err_sum, err_long % (required.size_total,
-                                                      required.dir,
-                                                      required.size_needed,
-                                                      required.dir))
+                self._view.error(err_sum, err_long.format(required.size_total,
+                                                          required.dir,
+                                                          required.size_needed,
+                                                          required.dir))
             return False
         return True
 
@@ -1172,7 +1174,7 @@
                                  "http://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+filebug "
                                  "and attach the files in /var/log/dist-upgrade/ "
                                  "to the bug report.\n"
-                                 "%s" % e)
+                                 "{0}".format(e))
                 self._view.error(_("Could not install the upgrades"), msg)
                 # installing the packages failed, can't be retried
                 cmd = ["/usr/bin/dpkg","--configure","-a"]
@@ -1208,7 +1210,7 @@
                          _("The upgrade has aborted. Please check your "\
                            "Internet connection or "\
                            "installation media and try again. "),
-                           "%s" % e)
+                           "{0}".format(e))
         # abort here because we want our sources.list back
         self.abort()
 
@@ -1301,7 +1303,7 @@
                                  _("A problem occurred during the clean-up. "
                                    "Please see the below message for more "
                                    "information. "),
-                                   "%s" % e)
+                                   "{0}".format(e))
         # run stuff after cleanup
         self.quirks.run("PostCleanup")
         # run the post upgrade scripts that can do fixup like xorg.conf
@@ -1375,8 +1377,8 @@
                 # FIXME: instead of error out, fetch and install it
                 #        here
                 self._view.error(_("Required depends is not installed"),
-                                 _("The required dependency '%s' is not "
-                                   "installed. " % dep))
+                                 _("The required dependency '{0}' is not "
+                                   "installed. ".format(dep)))
                 sys.exit(1)
         return res 
 
@@ -1755,7 +1757,7 @@
                 logging.error("No '%s' available/downloadable after sources.list rewrite+update" % pkg)
                 self._view.error(_("Invalid package information"),
                                  _("After updating your package "
-                                   "information, the essential package '%s' "
+                                   "information, the essential package '{0}' "
                                    "could not be located. This may be "
                                    "because you have no official mirrors "
                                    "listed in your software sources, or "
@@ -1765,8 +1767,7 @@
                                    "software sources."
                                    "\n"
                                    "In the case of an overloaded mirror, you "
-                                   "may want to try the upgrade again later.")
-                                   % pkg)
+                                   "may want to try the upgrade again later.").format(pkg))
                 if os.path.exists("/usr/bin/apport-bug"):
                     subprocess.Popen(["apport-bug", "ubuntu-release-upgrader-core"])
                 else:
 
=== modified file 'DistUpgrade/DistUpgradeFetcherCore.py'
--- DistUpgrade/DistUpgradeFetcherCore.py	2014-02-25 00:14:50 +0000
+++ DistUpgrade/DistUpgradeFetcherCore.py	2014-04-24 08:46:39 +0000
@@ -72,9 +72,9 @@
             f = self.tmpdir + "/" + os.path.basename(self.new_dist.upgradeTool)
             sig = self.tmpdir + "/" + os.path.basename(
                 self.new_dist.upgradeToolSig)
-            print(_("authenticate '%(file)s' against '%(signature)s' ") % {
-                'file': os.path.basename(f),
-                'signature': os.path.basename(sig)})
+            print(_("authenticate '{file}' against '{signature}' ").format(
+                file=os.path.basename(f),
+                signature=os.path.basename(sig)))
             if self.gpgauthenticate(f, sig):
                 return True
         return False
@@ -136,7 +136,7 @@
     def extractDistUpgrader(self):
         # extract the tarball
         fname = os.path.join(self.tmpdir, os.path.basename(self.uri))
-        print(_("extracting '%s'") % os.path.basename(fname))
+        print(_("extracting '{0}'").format(os.path.basename(fname)))
         if not os.path.exists(fname):
             return False
         try:
@@ -316,7 +316,7 @@
                 return False
             else:
                 self.error(_("Can not run the upgrade"),
-                           _("The error message is '%s'.") % e.strerror)
+                           _("The error message is '{0}'.").format(e.strerror))
         return True
 
 if __name__ == "__main__":
 
=== modified file 'DistUpgrade/DistUpgradeFetcherKDE.py'
--- DistUpgrade/DistUpgradeFetcherKDE.py	2014-02-25 00:28:19 +0000
+++ DistUpgrade/DistUpgradeFetcherKDE.py	2014-04-24 08:46:39 +0000
@@ -157,18 +157,19 @@
             current_item = self.total_items
         label_text = _("Downloading additional package files...")
         if self.current_cps > 0:
-            label_text += _("File %s of %s at %sB/s") % (
+            label_text += _("File {0} of {1} at {2}B/s").format(
                 self.current_items, self.total_items,
                 apt_pkg.size_to_str(self.current_cps))
         else:
-            label_text += _("File %s of %s") % (
+            label_text += _("File {0} of {1}").format(
                 self.current_items, self.total_items)
         self.label.setText(label_text)
         KApplication.kApplication().processEvents()
         return True
 
     def mediaChange(self, medium, drive):
-        msg = _("Please insert '%s' into the drive '%s'") % (medium, drive)
+        msg = _("Please insert '{0}' into the drive '{1}'").format(
+            medium, drive)
         #change = QMessageBox.question(None, _("Media Change"), msg,
         #                              QMessageBox.Ok, QMessageBox.Cancel)
         change = KMessageBox.questionYesNo(None, _("Media Change"),
 
=== modified file 'DistUpgrade/DistUpgradeGettext.py'
--- DistUpgrade/DistUpgradeGettext.py	2012-06-13 11:40:17 +0000
+++ DistUpgrade/DistUpgradeGettext.py	2014-04-24 08:46:39 +0000
@@ -64,7 +64,9 @@
         return ""
     translated_msg = unicode_gettext(_translation(), message)
     if not _verify(message, translated_msg):
-        logging.error("incorrect translation for message '%s' to '%s' (wrong number of arguments)" % (message, translated_msg))
+        logging.error(
+            "incorrect translation for message '{0}' to '{1}' "
+            "(wrong number of arguments)".format(message, translated_msg))
         return message
     return translated_msg
 
@@ -75,7 +77,10 @@
     """
     translated_msg = unicode_ngettext(_translation(), msgid1, msgid2, n)
     if not _verify(msgid1, translated_msg):
-        logging.error("incorrect translation for ngettext message '%s' plural: '%s' to '%s' (wrong number of arguments)" % (msgid1, msgid2, translated_msg))
+        logging.error(
+            "incorrect translation for ngettext message '{0}' "
+            "plural: '{1}' to '{2}' (wrong number of arguments)".format(
+                msgid1, msgid2, translated_msg))
         # dumb fallback to not crash
         if n == 1:
             return msgid1
 
=== modified file 'DistUpgrade/DistUpgradeView.py'
--- DistUpgrade/DistUpgradeView.py	2014-04-14 16:16:56 +0000
+++ DistUpgrade/DistUpgradeView.py	2014-04-24 08:46:39 +0000
@@ -76,12 +76,12 @@
   # get the fragments, this is not ideal i18n wise, but its
   # difficult to do it differently
   if days > 0:
-    map["str_days"] = ngettext("%li day","%li days", days) % days
+    map["str_days"] = ngettext("{0} day","{0} days", days).format(days)
   if hours > 0:
-    map["str_hours"] = ngettext("%li hour","%li hours", hours) % hours
+    map["str_hours"] = ngettext("{0} hour","{0} hours", hours).format(hours)
   if minutes > 0:
-    map["str_minutes"] = ngettext("%li minute","%li minutes", minutes) % minutes
-  map["str_seconds"] = ngettext("%li second","%li seconds", seconds) % seconds
+    map["str_minutes"] = ngettext("{0} minute","{0} minutes", minutes).format(minutes)
+  map["str_seconds"] = ngettext("{0} second","{0} seconds", seconds).format(seconds)
 
   # now assemble the string
   if days > 0:
@@ -97,7 +97,8 @@
     # plural form
     # 
     # Note: most western languages will not need to change this
-    return _("%(str_days)s %(str_hours)s") % map
+    return _("{str_days} {str_hours}").format(str_days=map["str_days"],
+                                              str_hours=map["str_hours"])
   # display no minutes for time > 3h, see LP: #144455
   elif hours > 3:
     return map["str_hours"]
@@ -115,7 +116,9 @@
     # plural form
     # 
     # Note: most western languages will not need to change this
-    return _("%(str_hours)s %(str_minutes)s") % map
+    return _("{str_hours} {str_minutes}").format(
+        str_hours=map["str_hours"],
+        str_minutes=map["str_minutes"])
   elif minutes > 0:
     return map["str_minutes"]
   return map["str_seconds"]
@@ -166,11 +169,11 @@
     if self.est_speed == 0:
       timeModem = required_download/(56*1024/8)  # 56 kbit 
       timeDSL = required_download/(1024*1024/8)  # 1Mbit = 1024 kbit
-      s= _("This download will take about %s with a 1Mbit DSL connection "
-           "and about %s with a 56k modem.") % (FuzzyTimeToStr(timeDSL), FuzzyTimeToStr(timeModem))
+      s= _("This download will take about {0} with a 1Mbit DSL connection "
+           "and about {1} with a 56k modem.").format(FuzzyTimeToStr(timeDSL), FuzzyTimeToStr(timeModem))
       return s
     # if we have a estimated speed, use it
-    s = _("This download will take about %s with your connection. ") % FuzzyTimeToStr(required_download/self.est_speed)
+    s = _("This download will take about {0} with your connection. ").format(FuzzyTimeToStr(required_download/self.est_speed))
     return s
     
 
@@ -366,35 +369,35 @@
         # FIXME: show detailed packages
         if len(self.demotions) > 0:
           msg += ngettext(
-            "%(amount)d installed package is no longer supported by Canonical. "
-            "You can still get support from the community.",
-            "%(amount)d installed packages are no longer supported by "
-            "Canonical. You can still get support from the community.",
-            len(self.demotions)) % { 'amount' : len(self.demotions) }
+              "{amount} installed package is no longer supported by Canonical. "
+              "You can still get support from the community.",
+              "{amount} installed packages are no longer supported by "
+              "Canonical. You can still get support from the community.",
+              len(self.demotions)).format(amount=len(self.demotions))
           msg += "\n\n"
         if pkgs_remove > 0:
           # FIXME: make those two separate lines to make it clear
           #        that the "%" applies to the result of ngettext
-          msg += ngettext("%d package is going to be removed.",
-                          "%d packages are going to be removed.",
-                          pkgs_remove) % pkgs_remove
+          msg += ngettext("{0} package is going to be removed.",
+                          "{0} packages are going to be removed.",
+                          pkgs_remove).format(pkgs_remove)
           msg += " "
         if pkgs_inst > 0:
-          msg += ngettext("%d new package is going to be "
+          msg += ngettext("{0} new package is going to be "
                           "installed.",
-                          "%d new packages are going to be "
-                          "installed.",pkgs_inst) % pkgs_inst
+                          "{0} new packages are going to be "
+                          "installed.",pkgs_inst).format(pkgs_inst)
           msg += " "
         if pkgs_upgrade > 0:
-          msg += ngettext("%d package is going to be upgraded.",
-                          "%d packages are going to be upgraded.",
-                          pkgs_upgrade) % pkgs_upgrade
+          msg += ngettext("{0} package is going to be upgraded.",
+                          "{0} packages are going to be upgraded.",
+                          pkgs_upgrade).format(pkgs_upgrade)
           msg +=" "
         if downloadSize > 0:
           downloadSizeStr = apt_pkg.size_to_str(downloadSize)
           if isinstance(downloadSizeStr, bytes):
               downloadSizeStr = downloadSizeStr.decode(ENCODING)
-          msg += _("\n\nYou have to download a total of %s. ") % (
+          msg += _("\n\nYou have to download a total of {0}. ").format(
               downloadSizeStr)
           msg += self.getAcquireProgress().estimatedDownloadTime(downloadSize)
         if ((pkgs_upgrade + pkgs_inst) > 0) and ((pkgs_upgrade + pkgs_inst + pkgs_remove) > 100):
 
=== modified file 'DistUpgrade/DistUpgradeViewGtk3.py'
--- DistUpgrade/DistUpgradeViewGtk3.py	2014-04-24 08:42:34 +0000
+++ DistUpgrade/DistUpgradeViewGtk3.py	2014-04-24 08:46:39 +0000
@@ -112,7 +112,7 @@
         self.canceled = True
     def media_change(self, medium, drive):
         #print("mediaChange %s %s" % (medium, drive))
-        msg = _("Please insert '%s' into the drive '%s'") % (medium,drive)
+        msg = _("Please insert '{0}' into the drive '{0}'").format(medium,drive)
         dialog = Gtk.MessageDialog(parent=self.parent.window_main,
                                    flags=Gtk.DialogFlags.MODAL,
                                    type=Gtk.MessageType.QUESTION,
@@ -148,12 +148,13 @@
                 if isinstance(current_cps, bytes):
                     current_cps = current_cps.decode(
                         locale.getpreferredencoding())
-                self.status.set_text(_("Fetching file %li of %li at %sB/s") % (
-                    currentItem, self.total_items, current_cps))
-                self.progress.set_text(_("About %s remaining") % FuzzyTimeToStr(
-                    self.eta))
+                self.status.set_text(
+                    _("Fetching file {0} of {1} at {2}B/s").format(
+                        currentItem, self.total_items, current_cps))
+                self.progress.set_text(_("About {0} remaining").format(
+                    FuzzyTimeToStr(self.eta)))
             else:
-                self.status.set_text(_("Fetching file %li of %li") % (
+                self.status.set_text(_("Fetching file {0} of {1}").format(
                     currentItem, self.total_items))
                 self.progress.set_text("  ")
         while Gtk.events_pending():
@@ -215,11 +216,11 @@
 
         #self.expander_terminal.set_expanded(True)
         self.parent.dialog_error.set_transient_for(self.parent.window_main)
-        summary = _("Could not install '%s'") % pkg
-        msg = _("The upgrade will continue but the '%s' package may not "
+        summary = _("Could not install '{0}'").format(pkg)
+        msg = _("The upgrade will continue but the '{0}' package may not "
                 "be in a working state. Please consider submitting a "
-                "bug report about it.") % pkg
-        markup="<big><b>%s</b></big>\n\n%s" % (summary, msg)
+                "bug report about it.").format(pkg)
+        markup="<big><b>{0}</b></big>\n\n{1}".format(summary, msg)
         self.parent.dialog_error.realize()
         self.parent.dialog_error.set_title("")
         self.parent.dialog_error.get_window().set_functions(Gdk.WMFunction.MOVE)
@@ -233,11 +234,12 @@
         logging.debug("got a conffile-prompt from dpkg for file: '%s'" % current)
         start = time.time()
         #self.expander.set_expanded(True)
-        prim = _("Replace the customized configuration file\n'%s'?") % current
+        prim = _("Replace the customized configuration file\n'{0}'?").format(
+            current)
         sec = _("You will lose any changes you have made to this "
                 "configuration file if you choose to replace it with "
                 "a newer version.")
-        markup = "<span weight=\"bold\" size=\"larger\">%s </span> \n\n%s" % (prim, sec)
+        markup = "<span weight=\"bold\" size=\"larger\">{0} </span> \n\n{1}".format(prim, sec)
         self.parent.label_conffile.set_markup(markup)
         self.parent.dialog_conffile.set_title("")
         self.parent.dialog_conffile.set_transient_for(self.parent.window_main)
@@ -254,7 +256,8 @@
             diff = diff.decode("UTF-8", "replace")
             self.parent.textview_conffile.get_buffer().set_text(diff)
         else:
-            self.parent.textview_conffile.get_buffer().set_text(_("The 'diff' command was not found"))
+            self.parent.textview_conffile.get_buffer().set_text(
+                _("The 'diff' command was not found"))
         res = self.parent.dialog_conffile.run()
         self.parent.dialog_conffile.hide()
         self.time_ui += time.time() - start
@@ -307,7 +310,8 @@
             eta = (100.0 - percent) * time_per_percent
             # only show if we have some sensible data (60sec < eta < 2days)
             if eta > 61.0 and eta < (60*60*24*2):
-                self.progress.set_text(_("About %s remaining") % FuzzyTimeToStr(eta))
+                self.progress.set_text(
+                    _("About {0} remaining").format(FuzzyTimeToStr(eta)))
             else:
                 self.progress.set_text(" ")
             # 2 == WEBKIT_LOAD_FINISHED - the enums is not exposed via python
@@ -652,16 +656,16 @@
         # fill in the details
         self.details_list.clear()
         for (parent_text, details_list) in (
-            ( _("No longer supported by Canonical (%s)"), self.demotions),
-            ( _("<b>Downgrade (%s)</b>"), self.toDowngrade),
-            ( _("Remove (%s)"), self.toRemove),
-            ( _("No longer needed (%s)"), self.toRemoveAuto),
-            ( _("Install (%s)"), self.toInstall),
-            ( _("Upgrade (%s)"), self.toUpgrade),
+                ( _("No longer supported by Canonical ({0})"), self.demotions),
+                ( _("<b>Downgrade ({0})</b>"), self.toDowngrade),
+                ( _("Remove ({0})"), self.toRemove),
+                ( _("No longer needed ({0})"), self.toRemoveAuto),
+                ( _("Install ({0})"), self.toInstall),
+                ( _("Upgrade ({0})"), self.toUpgrade),
           ):
             if details_list:
                 node = self.details_list.append(None,
-                                                [parent_text % len(details_list)])
+                                                [parent_text.format(len(details_list))])
                 for pkg in details_list:
                     self.details_list.append(node, ["<b>%s</b> - %s" % (
                           pkg.name, GLib.markup_escape_text(getattr(pkg.candidate, "summary", None)))])
 
=== modified file 'DistUpgrade/DistUpgradeViewKDE.py'
--- DistUpgrade/DistUpgradeViewKDE.py	2012-10-09 16:35:12 +0000
+++ DistUpgrade/DistUpgradeViewKDE.py	2014-04-24 08:46:39 +0000
@@ -193,7 +193,7 @@
         self.parent = parent
 
     def media_change(self, medium, drive):
-      msg = _("Please insert '%s' into the drive '%s'") % (medium,drive)
+      msg = _("Please insert '{0}' into the drive '{1}'").format(medium,drive)
       change = QMessageBox.question(self.parent.window_main, _("Media Change"), msg, QMessageBox.Ok, QMessageBox.Cancel)
       if change == QMessageBox.Ok:
         return True
@@ -223,10 +223,15 @@
             current_cps = apt_pkg.size_to_str(self.current_cps)
             if isinstance(current_cps, bytes):
                 current_cps = current_cps.decode(locale.getpreferredencoding())
-            self.status.setText(_("Fetching file %li of %li at %sB/s") % (current_item, self.total_items, current_cps))
-            self.parent.window_main.progress_text.setText("<i>" + _("About %s remaining") % FuzzyTimeToStr(self.eta) + "</i>")
+            self.status.setText(_("Fetching file {0} of {1} at {2}B/s").format(
+                current_item, self.total_items, current_cps))
+            self.parent.window_main.progress_text.setText(
+                "<i>" + _("About {0} remaining").format(
+                    FuzzyTimeToStr(self.eta)) +
+                "</i>")
         else:
-            self.status.setText(_("Fetching file %li of %li") % (current_item, self.total_items))
+            self.status.setText(_("Fetching file {0} of {1}").format(
+                current_item, self.total_items))
             self.parent.window_main.progress_text.setText("  ")
 
         QApplication.processEvents()
@@ -278,10 +283,10 @@
         # we do not report followup errors from earlier failures
         if gettext.dgettext('dpkg', "dependency problems - leaving unconfigured") in errormsg:
           return False
-        summary = _("Could not install '%s'") % pkg
-        msg = _("The upgrade will continue but the '%s' package may not "
+        summary = _("Could not install '{0}'").format(pkg)
+        msg = _("The upgrade will continue but the '{0}' package may not "
                 "be in a working state. Please consider submitting a "
-                "bug report about it.") % pkg
+                "bug report about it.").format(pkg)
         msg = "<big><b>%s</b></big><br />%s" % (summary, msg)
 
         dialogue = QDialog(self.parent.window_main)
@@ -300,11 +305,13 @@
         """ask question in case conffile has been changed by user"""
         logging.debug("got a conffile-prompt from dpkg for file: '%s'" % current)
         start = time.time()
-        prim = _("Replace the customized configuration file\n'%s'?") % current
+        prim = _("Replace the customized configuration file\n'{0}'?").format(
+            current)
         sec = _("You will lose any changes you have made to this "
                 "configuration file if you choose to replace it with "
                 "a newer version.")
-        markup = "<span weight=\"bold\" size=\"larger\">%s </span> \n\n%s" % (prim, sec)
+        markup = "<span weight=\"bold\" size=\"larger\">{0} </span> "\
+                 "\n\n{1}".format(prim, sec)
         self.confDialogue = QDialog(self.parent.window_main)
         loadUi("dialog_conffile.ui", self.confDialogue)
         self.confDialogue.label_conffile.setText(markup)
@@ -372,7 +379,8 @@
           eta = (100.0 - self.percent) * time_per_percent
           # only show if we have some sensible data (60sec < eta < 2days)
           if eta > 61.0 and eta < (60*60*24*2):
-            self.progress_text.setText(_("About %s remaining") % FuzzyTimeToStr(eta))
+            self.progress_text.setText(_("About {0} remaining").format(
+                FuzzyTimeToStr(eta)))
           else:
             self.progress_text.setText(" ")
 
@@ -778,15 +786,15 @@
         self.changesDialogue.treeview_details.setHeaderLabels(["Packages"])
         self.changesDialogue.treeview_details.header().hide()
         for demoted in self.demotions:
-            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("No longer supported %s") % demoted.name]) )
+            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("No longer supported {0}").format(demoted.name)]) )
         for rm in self.toRemove:
-            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Remove %s") % rm.name]) )
+            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Remove {0}").format(rm.name)]) )
         for rm in self.toRemoveAuto:
-            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Remove (was auto installed) %s") % rm.name]) )
+            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Remove (was auto installed) {0}").format(rm.name)]) )
         for inst in self.toInstall:
-            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Install %s") % inst.name]) )
+            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Install {0}").format(inst.name)]) )
         for up in self.toUpgrade:
-            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Upgrade %s") % up.name]) )
+            self.changesDialogue.treeview_details.insertTopLevelItem(0, QTreeWidgetItem(self.changesDialogue.treeview_details, [_("Upgrade {0}").format(up.name)]) )
 
         #FIXME resize label, stop it being shrinkable
         res = self.changesDialogue.exec_()
 
=== modified file 'DistUpgrade/DistUpgradeViewText.py'
--- DistUpgrade/DistUpgradeViewText.py	2014-04-14 12:14:57 +0000
+++ DistUpgrade/DistUpgradeViewText.py	2014-04-24 08:46:39 +0000
@@ -196,27 +196,32 @@
           if len(self.demotions) > 0:
               output += "\n"  
               output += twrap(
-                  _("No longer supported: %s\n") % " ".join([p.name for p in self.demotions]),
+                  _("No longer supported: {0}\n").format(
+                      " ".join([p.name for p in self.demotions])),
                   subsequent_indent='  ')
           if len(self.toRemove) > 0:
               output += "\n"  
               output += twrap(
-                  _("Remove: %s\n") % " ".join([p.name for p in self.toRemove]),
+                  _("Remove: {0}\n").format(
+                      " ".join([p.name for p in self.toRemove])),
                   subsequent_indent='  ')
           if len(self.toRemoveAuto) > 0:
               output += twrap(
-                  _("Remove (was auto installed) %s") % " ".join([p.name for p in self.toRemoveAuto]), 
+                  _("Remove (was auto installed) {0}").format(
+                      " ".join([p.name for p in self.toRemoveAuto])),
                   subsequent_indent='  ')
               output += "\n"
           if len(self.toInstall) > 0:
               output += "\n"
               output += twrap(
-                  _("Install: %s\n") % " ".join([p.name for p in self.toInstall]),
+                  _("Install: {0}\n").format(
+                      " ".join([p.name for p in self.toInstall])),
                   subsequent_indent='  ')
           if len(self.toUpgrade) > 0:
               output += "\n"  
               output += twrap(
-                  _("Upgrade: %s\n") % " ".join([p.name for p in self.toUpgrade]),
+                  _("Upgrade: {0}\n").format(
+                      " ".join([p.name for p in self.toUpgrade])),
                   subsequent_indent='  ')
           self.showInPager(output)
         print("%s %s" % (_("Continue [yN] "), _("Details [d]")), end="")
 
=== modified file 'DistUpgrade/GtkProgress.py'
--- DistUpgrade/GtkProgress.py	2013-01-15 15:51:10 +0000
+++ DistUpgrade/GtkProgress.py	2014-04-24 08:46:39 +0000
@@ -70,15 +70,15 @@
         if current_item > self.total_items:
             current_item = self.total_items
         if self.current_cps > 0:
-            status_text = (_("Downloading file %(current)li of %(total)li "
-                             "with %(speed)s/s") % {
-                                 "current": current_item,
-                                 "total": self.total_items,
-                                 "speed": humanize_size(self.current_cps)})
+            status_text = (_("Downloading file {current} of {total} "
+                             "with {speed}/s").format(
+                                 current=current_item,
+                                 total=self.total_items,
+                                 speed=humanize_size(self.current_cps)))
         else:
-            status_text = (_("Downloading file %(current)li of %(total)li") %
-                           {"current": current_item,
-                            "total": self.total_items})
+            status_text = (_("Downloading file {current} of {total}").format(
+                           current=current_item,
+                           total=self.total_items))
             self.progress.set_fraction(
                 (self.current_bytes + self.current_items) /
                 float(self.total_bytes + self.total_items))
 
=== modified file 'check-new-release-gtk'
--- check-new-release-gtk	2013-10-05 02:17:39 +0000
+++ check-new-release-gtk	2014-04-24 08:46:39 +0000
@@ -73,7 +73,7 @@
     self.options = options
     self.datadir = options.datadir
     self.new_dist = None
-    logging.debug("running with devel=%s proposed=%s" % (
+    logging.debug("running with devel={0} proposed={0}".format(
             options.devel_release, options.proposed_release))
     m = MetaRelease(useDevelopmentRelease=options.devel_release,
                     useProposed=options.proposed_release)
@@ -93,7 +93,7 @@
     Gtk.main()
 
   def new_dist_available(self, meta_release, new_dist):
-    logging.debug("new_dist_available: %s" % new_dist)
+    logging.debug("new_dist_available: {0}".format(new_dist))
     self.new_dist = new_dist
     client =  Gio.Settings("com.ubuntu.update-manager")
     ignore_dist = client.get_string("check-new-release-ignore")
@@ -101,7 +101,7 @@
     # go into nag mode
     if (ignore_dist == new_dist.name and
         meta_release.no_longer_supported is None):
-        logging.warn("found new dist '%s' but it is on the ignore list" % new_dist.name)
+        logging.warn("found new dist '{0}' but it is on the ignore list".format(new_dist.name))
         sys.exit()
 
     # show alert on unsupported distros
@@ -110,7 +110,7 @@
         Gtk.main_quit()
     else:
         self.build_ui()
-        self.window_main.set_title(_("Ubuntu %(version)s Upgrade Available") % {'version': new_dist.version})
+        self.window_main.set_title(_("Ubuntu {version} Upgrade Available").format(version=new_dist.version))
         self.window_main.show()
 
   def close(self):
@@ -129,7 +129,7 @@
         extra_args = extra_args + " --proposed"
     os.execl("/bin/sh", "/bin/sh", "-c",
              "/usr/bin/pkexec /usr/bin/do-release-upgrade "
-             "--frontend=DistUpgradeViewGtk3%s" % extra_args)
+             "--frontend=DistUpgradeViewGtk3{0}".format(extra_args))
 
   def on_button_ask_me_later_clicked(self, button):
     logging.debug("ask me later")
@@ -141,8 +141,9 @@
 
   def on_button_dont_upgrade_clicked(self, button):
     #print("don't upgrade")
-    s = _("You have declined the upgrade to Ubuntu %s") % self.new_dist.version
-    self.dialog_really_do_not_upgrade.set_markup("<b>%s</b>" % s)
+    s = _("You have declined the upgrade to Ubuntu {0}").format(
+      self.new_dist.version)
+    self.dialog_really_do_not_upgrade.set_markup("<b>{0}</b>".format(s))
     if self.dialog_really_do_not_upgrade.run() == Gtk.ResponseType.OK:
         client = Gio.Settings("com.ubuntu.update-manager")
         client.set_string("check-new-release-ignore", self.new_dist.name)
 
=== modified file 'do-partial-upgrade'
--- do-partial-upgrade	2012-06-28 19:22:04 +0000
+++ do-partial-upgrade	2014-04-24 08:46:39 +0000
@@ -77,7 +77,7 @@
     data_dir = os.path.normpath(options.data_dir)+"/"
 
     if options.show_version:
-        print("%s: version %s" % (os.path.basename(sys.argv[0]), VERSION))
+        print("{0}: version {1}".format(os.path.basename(sys.argv[0]), VERSION))
         sys.exit(0)
 
     module_name = "DistUpgrade." + options.frontend
@@ -86,7 +86,7 @@
     view_class = getattr(submodule, options.frontend)
     view = view_class(data_dir)
     if options.frontend == "DistUpgradeViewGtk3":
-        view.label_title.set_markup("<b><big>%s</big></b>" %
-                                    _("Running partial upgrade"))
+        view.label_title.set_markup("<b><big>{0}</big></b>".format(
+                                    _("Running partial upgrade")))
     controller = DistUpgradeController(view, datadir=data_dir)
     controller.doPartialUpgrade()
 
=== modified file 'pre-build.sh'
--- pre-build.sh	2014-04-07 12:30:43 +0000
+++ pre-build.sh	2014-04-24 08:46:39 +0000
@@ -8,6 +8,11 @@
 dpkg-checkbuilddeps -d 'python3-apt, apt-btrfs-snapshot, parsewiki, python-feedparser,
 			python3-mock, xvfb, gir1.2-gtk-3.0, python3-gi, python3-nose'
 
+# check the po files (LP: #1311396)
+for po in po/*.po; do
+    msgfmt -c $po
+done
+
 # update demotions
 (cd utils && ./demotions.py saucy trusty > demoted.cfg)
 # when this gets enabled, make sure to add symlink in DistUpgrade