This file is indexed.

/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py is in python3-software-properties 0.96.20.2-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
#  software-properties backend
#
#  Copyright (c) 2004-2007 Canonical Ltd.
#                2004-2005 Michiel Sikkes
#
#  Author: Michiel Sikkes <michiel@eyesopened.nl>
#          Michael Vogt <mvo@debian.org>
#          Sebastian Heinlein <glatzor@ubuntu.com>
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License as
#  published by the Free Software Foundation; either version 2 of the
#  License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
#  USA

from __future__ import absolute_import, print_function

import apt_pkg
import copy
from hashlib import md5
import re
import os
import glob
import shutil
import threading
import atexit
import tempfile
try:
  from string import maketrans
except ImportError:
  maketrans = str.maketrans
import stat

from tempfile import NamedTemporaryFile
from xml.sax.saxutils import escape
try:
  from configparser import ConfigParser
except ImportError:
  from ConfigParser import ConfigParser
from gettext import gettext as _

import aptsources
import aptsources.distro
import softwareproperties

from .AptAuth import AptAuth
from aptsources.sourceslist import SourcesList, SourceEntry
from . import shortcuts
from . import ppa
from . import cloudarchive

_SHORTCUT_FACTORIES = [
    ppa.shortcut_handler,
    cloudarchive.shortcut_handler,
    shortcuts.shortcut_handler,
]


class SoftwareProperties(object):

  # known (whitelisted) channels
  CHANNEL_PATH="/usr/share/app-install/channels/"

  # release upgrades policy
  RELEASE_UPGRADES_CONF = "/etc/update-manager/release-upgrades"
  #RELEASE_UPGRADES_CONF = "/tmp/release-upgrades"
  (
    RELEASE_UPGRADES_NORMAL,
    RELEASE_UPGRADES_LTS,
    RELEASE_UPGRADES_NEVER
  ) = list(range(3))
  release_upgrades_policy_map = {
    RELEASE_UPGRADES_NORMAL : 'normal',
    RELEASE_UPGRADES_LTS    : 'lts',
    RELEASE_UPGRADES_NEVER  : 'never',
  }
  
  def __init__(self, datadir=None, options=None, rootdir="/"):
    """ Provides the core functionality to configure the used software 
        repositories, the corresponding authentication keys and 
        update automation """
    self.popconfile = rootdir+"/etc/popularity-contest.conf"

    self.rootdir = rootdir
    if rootdir != "/":
      apt_pkg.config.set("Dir", rootdir)

    # FIXME: some saner way is needed here
    if datadir == None:
      datadir = "/usr/share/software-properties/"
    self.options = options
    self.datadir = datadir

    self.sourceslist = SourcesList()
    self.distro = aptsources.distro.get_distro()
    
    self.seen_server = []
    self.modified_sourceslist = False

    self.reload_sourceslist()
    self.backup_sourceslist()

    self.backup_apt_conf()

    # FIXME: we need to store this value in a config option
    #self.custom_mirrors = ["http://adasdwww.de/ubuntu"]
    self.custom_mirrors= []

    # apt-key stuff
    self.apt_key = AptAuth(rootdir=rootdir)

    atexit.register(self.wait_for_threads)

  def wait_for_threads(self):
    " wait for all running threads (PPA key fetchers) to exit "
    for t in threading.enumerate():
      if t.ident != threading.current_thread().ident:
        t.join()

  def backup_apt_conf(self):
    """Backup all apt configuration options"""
    self.apt_conf_backup = {}
    for option in softwareproperties.CONF_MAP.keys():
        value = apt_pkg.config.find_i(softwareproperties.CONF_MAP[option])
        self.apt_conf_backup[option] = value

  def restore_apt_conf(self):
    """Restore the stored apt configuration"""
    for option in self.apt_conf_backup.keys():
        apt_pkg.config.set(softwareproperties.CONF_MAP[option],
                           str(self.apt_conf_backup[option]))
    self.write_config()

  def get_update_automation_level(self):
    """ Parse the apt cron configuration. Try to fit a predefined use case 
        and return it. Special case: if the user made a custom 
        configurtation, that we cannot represent it will return None """
    if apt_pkg.config.find_i(softwareproperties.CONF_MAP["autoupdate"]) > 0:
        # Autodownload
        if apt_pkg.config.find_i(softwareproperties.CONF_MAP["unattended"]) == 1\
           and os.path.exists("/usr/bin/unattended-upgrade"):
            return softwareproperties.UPDATE_INST_SEC
        elif apt_pkg.config.find_i(softwareproperties.CONF_MAP["autodownload"]) == 1 and  \
             apt_pkg.config.find_i(softwareproperties.CONF_MAP["unattended"]) == 0:
            return softwareproperties.UPDATE_DOWNLOAD
        elif apt_pkg.config.find_i(softwareproperties.CONF_MAP["unattended"]) == 0 and \
             apt_pkg.config.find_i(softwareproperties.CONF_MAP["autodownload"]) == 0:
            return softwareproperties.UPDATE_NOTIFY
        else:
            return None
    elif apt_pkg.config.find_i(softwareproperties.CONF_MAP["unattended"]) == 0 and \
         apt_pkg.config.find_i(softwareproperties.CONF_MAP["autodownload"]) == 0:
        return softwareproperties.UPDATE_MANUAL
    else:
        return None

  def set_update_automation_level(self, state):
    """ Set the apt periodic configurtation to the selected 
        update automation level. To synchronize the cache update and the 
        actual upgrading function, the upgrade function, e.g. unattended, 
        will run every day, if enabled. """
    if state == softwareproperties.UPDATE_INST_SEC:
        apt_pkg.config.set(softwareproperties.CONF_MAP["unattended"], str(1))
        apt_pkg.config.set(softwareproperties.CONF_MAP["autodownload"], str(1))
    elif state == softwareproperties.UPDATE_DOWNLOAD:
        apt_pkg.config.set(softwareproperties.CONF_MAP["autodownload"], str(1))
        apt_pkg.config.set(softwareproperties.CONF_MAP["unattended"], str(0))
    elif state == softwareproperties.UPDATE_NOTIFY:
        apt_pkg.config.set(softwareproperties.CONF_MAP["autodownload"], str(0))
        apt_pkg.config.set(softwareproperties.CONF_MAP["unattended"], str(0))
    else:
        apt_pkg.config.set(softwareproperties.CONF_MAP["autoupdate"], str(0))
        apt_pkg.config.set(softwareproperties.CONF_MAP["unattended"], str(0))
        apt_pkg.config.set(softwareproperties.CONF_MAP["autodownload"], str(0))
    self.set_modified_config()

  def set_update_interval(self, days):
      """Set the interval in which we check for available updates"""
      # Only write the key if it has changed
      if not days == apt_pkg.config.find_i(softwareproperties.CONF_MAP["autoupdate"]):
          apt_pkg.config.set(softwareproperties.CONF_MAP["autoupdate"], str(days))
          self.set_modified_config()

  def get_update_interval(self):
    """ Returns the interval of the apt periodic cron job """
    return apt_pkg.config.find_i(softwareproperties.CONF_MAP["autoupdate"])

  def get_release_upgrades_policy(self):
    """
    return the release upgrade policy:
     RELEASE_UPGRADES_NORMAL,
     RELEASE_UPGRADES_LTS,
     RELEASE_UPGRADES_NEVER
    """
    # default (if no option is set) is NORMAL
    if not os.path.exists(self.RELEASE_UPGRADES_CONF):
      return self.RELEASE_UPGRADES_NORMAL
    parser = ConfigParser()
    parser.read(self.RELEASE_UPGRADES_CONF)
    if parser.has_option("DEFAULT","Prompt"):
      type = parser.get("DEFAULT","Prompt").lower()
      for k, v in self.release_upgrades_policy_map.items():
        if v == type:
          return k
    return self.RELEASE_UPGRADES_NORMAL

  def set_release_upgrades_policy(self, i):
    """
    set the release upgrade policy:
     RELEASE_UPGRADES_NORMAL,
     RELEASE_UPGRADES_LTS,
     RELEASE_UPGRADES_NEVER
     """
    # we are note using ConfigParser.write() as it removes comments
    if not os.path.exists(self.RELEASE_UPGRADES_CONF):
      f = open(self.RELEASE_UPGRADES_CONF,"w")
      f.write("[DEFAULT]\nPrompt=%s\n"% self.release_upgrades_policy_map[i])
      return True
    f = open(self.RELEASE_UPGRADES_CONF,"r")
    out = NamedTemporaryFile(mode="w+")
    for line in f:
      line = line.strip()
      if line.lower().startswith("prompt"):
        out.write("Prompt=%s\n" % self.release_upgrades_policy_map[i])
      else:
        out.write(line+"\n")
    out.flush()
    shutil.copymode(self.RELEASE_UPGRADES_CONF, out.name)
    shutil.copy(out.name, self.RELEASE_UPGRADES_CONF)
    return True

  def get_popcon_participation(self):
    """ Will return True if the user wants to participate in the popularity 
        contest. Otherwise it will return False. Special case: if no 
        popcon is installed it will return False """
    if os.path.exists(self.popconfile):
        lines = open(self.popconfile).read().split("\n")
        active = False
        for line in lines:
            try:
                (key,value) = line.split("=")
                if key == "PARTICIPATE" and value.strip('"').lower() == "yes":
                    active = True
            except ValueError:
                continue
        return active
    else:
        return False

  def set_popcon_pariticipation(self, is_helpful):
    """ Enable or disable the participation in the popularity contest """
    if is_helpful == True:
        value = "yes"
    else:
        value = "no"
    if os.path.exists(self.popconfile):
        # read the current config and replace the corresponding settings
        # FIXME: should we check the other values, too?
        with open(self.popconfile, "r") as popconfile:
            lines = [re.sub(r'^(PARTICIPATE=)(".+?")', '\\1"%s"' % value, line)
                     for line in popconfile]
    else:
        # create a new popcon config file
        m = md5()
        m.update(open("/dev/urandom", "rb").read(1024))
        id = m.hexdigest()
        lines = []
        lines.append("MY_HOSTID=\"%s\"\n" % id)
        lines.append("PARTICIPATE=\"%s\"\n" % str(value))
        lines.append("USE_HTTP=\"yes\"\n")
    open(self.popconfile, "w").writelines(lines)

  def get_source_code_state(self):
    """Return True if all distro componets are also available as 
       source code. Otherwise return Flase. Special case: If the
       configuration cannot be represented return None"""
  
    if len(self.distro.source_code_sources) < 1:
        # we don't have any source code sources, so
        # uncheck the button
        self.distro.get_source_code = False
        return False
    else:
        # there are source code sources, so we check the button
        self.distro.get_source_code = True
        # check if there is a corresponding source code source for
        # every binary source. if not set the checkbutton to inconsistent
        templates = {}
        sources = []
        sources.extend(self.distro.main_sources)
        sources.extend(self.distro.child_sources)
        for source in sources:
            if source.template in templates:
                for comp in source.comps:
                    templates[source.template].add(comp)
            else:
                templates[source.template] = set(source.comps)
        # add fake http sources for the cdrom, since the sources
        # for the cdrom are only available in the internet
        if len(self.distro.cdrom_sources) > 0:
            templates[self.distro.source_template] = self.distro.cdrom_comps
        for source in self.distro.source_code_sources:
            if source.template not in templates or \
               (source.template in templates and not \
                (len(set(templates[source.template]) ^ set(source.comps)) == 0\
                 or (len(set(source.comps) ^ self.distro.enabled_comps) == 0))):
                self.distro.get_source_code = False
                return None
                break
    return True

  def print_source_entry(self, source):
    """Print the data of a source entry to the command line"""
    for (label, value) in [("URI:", source.uri),
                           ("Comps:", source.comps),
                           ("Enabled:", not source.disabled),
                           ("Valid:", not source.invalid)]:
        print(" %s %s" % (label, value))
    if source.template:
        for (label, value) in [("MatchURI:", source.template.match_uri),
                               ("BaseURI:", source.template.base_uri)]:
            print(" %s %s" % (label, value))
    print("\n")

  def massive_debug_output(self):
    """Print the complete sources.list""" 
    print("START SOURCES.LIST:")
    for source in self.sourceslist:
        print(source.str())
    print("END SOURCES.LIST\n")

  def change_main_download_server(self, server):
    """ change the main download server """
    self.distro.default_server = server
    res = self.distro.change_server(server)
    self.set_modified_sourceslist()
    return res

  def enable_component(self, comp):
    """Enable a component of the distro"""
    self.distro.enable_component(comp) 
    self.set_modified_sourceslist()

  def disable_component(self, comp):
    """Disable a component of the distro"""
    self.distro.disable_component(comp) 
    self.set_modified_sourceslist()

  def _find_template_from_string(self, name):
    for template in self.distro.source_template.children:
      if template.name == name:
        return template

  def disable_child_source(self, template):
    """Enable a child repo of the distribution main repository"""
    if isinstance(template, str):
      template = self._find_template_from_string(template)

    for source in self.distro.child_sources:
        if source.template == template:
            self.sourceslist.remove(source)
    for source in self.distro.source_code_sources:
        if source.template == template:
            self.sourceslist.remove(source)
    self.set_modified_sourceslist()

  def enable_child_source(self, template):
    """Enable a child repo of the distribution main repository"""
    if isinstance(template, str):
      template = self._find_template_from_string(template)

    # Use the currently selected mirror only if the child source
    # did not override the server
    if template.base_uri == None:
        child_uri = self.distro.default_server
    else:
        child_uri = template.base_uri
    self.distro.add_source(uri=child_uri, dist=template.name)
    self.set_modified_sourceslist()

  def disable_source_code_sources(self):
    """Remove all distro source code sources"""
    sources = []
    sources.extend(self.distro.main_sources)
    sources.extend(self.distro.child_sources)
    # remove all exisiting sources
    for source in self.distro.source_code_sources:
        self.sourceslist.remove(source)
    self.set_modified_sourceslist()
  
  def enable_source_code_sources(self):
    """Enable source code source for all distro sources"""
    sources = []
    sources.extend(self.distro.main_sources)
    sources.extend(self.distro.child_sources)

    # remove all exisiting sources
    for source in self.distro.source_code_sources:
        self.sourceslist.remove(source)

    for source in sources:
        self.sourceslist.add("deb-src",
                             source.uri,
                             source.dist,
                             source.comps,
                             "Added by software-properties",
                             self.sourceslist.list.index(source)+1,
                             source.file)
    for source in self.distro.cdrom_sources:
        self.sourceslist.add("deb-src",
                             self.distro.source_template.base_uri,
                             self.distro.source_template.name,
                             source.comps,
                             "Added by software-properties",
                             self.sourceslist.list.index(source)+1,
                             source.file)
    self.set_modified_sourceslist()

  def backup_sourceslist(self):
    """Store a backup of the source.list in memory"""
    self.sourceslist_backup = []
    for source in self.sourceslist.list:
        source_bkp = SourceEntry(line=source.line,file=source.file)
        self.sourceslist_backup.append(source_bkp)
  
  def _find_source_from_string(self, line):
    # ensure that we have a current list, it might have been changed underneath
    # us
    self.reload_sourceslist()

    for source in self.sourceslist.list:
      if str(source) == line:
        return source
    return None

  def toggle_source_use(self, source):
    """Enable or disable the selected channel"""
    #FIXME cdroms need to disable the comps in the childs and sources
    if isinstance(source, str):
      source = self._find_source_from_string(source)
    source.disabled = not source.disabled
    self.set_modified_sourceslist()

  def replace_source_entry(self, old_entry, new_entry):
    # find and replace, then write
    for (index, entry) in enumerate(self.sourceslist.list):
      if str(entry) == old_entry:
        file = self.sourceslist.list[index].file
        self.sourceslist.list[index] = SourceEntry(new_entry, file)
        self.set_modified_sourceslist()
        return True
    return False

  def revert(self):
    """Revert all settings to the state when software-properties 
       was launched"""
    #FIXME: GPG keys are still missing
    self.restore_apt_conf()
    self.revert_sourceslist()

  def revert_sourceslist(self):
    """Restore the source list from the startup of the dialog"""
    self.sourceslist.list = []
    for source in self.sourceslist_backup:
        source_reset = SourceEntry(line=source.line,file=source.file)
        self.sourceslist.list.append(source_reset)
    self.save_sourceslist()
    self.reload_sourceslist()

  def set_modified_sourceslist(self):
    """The sources list was changed and now needs to be saved and reloaded"""
    self.modified_sourceslist = True
    if self.options and self.options.massive_debug:
        self.massive_debug_output()
    self.save_sourceslist()
    self.reload_sourceslist()

  def set_modified_config(self):
    """Write the changed apt configuration to file"""
    self.write_config()

  def render_source(self, source):
    """Render a nice output to show the source in a treeview"""
    if source.template == None:
        if source.comment:
            contents = "<b>%s</b> %s" % (escape(source.comment).strip(),
                                         source.dist)
            # Only show the components if there are more than one
            if len(source.comps) > 1:
                for c in source.comps:
                    contents += " %s" % c
            if source.type in ("deb-src", "rpm-src"):
                contents += " %s" % _("(Source Code)")
            contents += "\n%s" % source.uri
        else:
            contents = "<b>%s %s</b>" % (source.uri, source.dist)
            for c in source.comps:
                contents += " %s" % c
            if source.type in ("deb-src", "rpm-src"):
                contents += " %s" % _("(Source Code)")
        return contents
    else:
        # try to make use of a corresponding template
        contents = "<b>%s</b>" % source.template.description
        if source.type in ("deb-src", "rpm-src"):
            contents += " (%s)" % _("Source Code")
        if source.comment:
            contents +=" %s" % source.comment
        if source.template.child == False:
            for comp in source.comps:
                if source.template.has_component(comp):
                    # fixme: move something like this into distinfo.Template
                    #        (why not use a dictionary again?)
                    for c in source.template.components:
                        if c.name == comp:
                            contents += "\n%s" % c.description
                else:
                    contents += "\n%s" % comp
        return contents

  def get_comparable(self, source):
      """extract attributes to sort the sources"""
      cur_sys = 1
      has_template = 1
      has_comment = 1
      is_source = 1
      revert_numbers = maketrans("0123456789", "9876543210")
      if source.template:
        has_template = 0
        desc = source.template.description
        if source.template.distribution == self.distro:
            cur_sys = 0
      else:
          desc = "%s %s %s" % (source.uri, source.dist, source.comps)
          if source.comment:
              has_comment = 0
      if source.type.find("src"):
          is_source = 0
      return (cur_sys, has_template, has_comment, is_source,
              desc.translate(revert_numbers))

  def get_isv_sources(self):
    """Return a list of sources that are not part of the distribution"""
    isv_sources = []
    for source in self.sourceslist.list:
        if not source.invalid and\
           (source not in self.distro.main_sources and\
            source not in self.distro.cdrom_sources and\
            source not in self.distro.child_sources and\
            source not in self.distro.disabled_sources) and\
           source not in self.distro.source_code_sources:
            isv_sources.append(source)
    return isv_sources

  def get_cdrom_sources(self):
    """Return the list of CDROM based distro sources"""
    return self.distro.cdrom_sources
      
  def get_comp_download_state(self, comp):
    """Return a tuple: the first value describes if a component is enabled
       in the Internet repositories. The second value describes if the
       first value is inconsistent."""
    #FIXME: also return a correct inconsistent value
    return (comp.name in self.distro.download_comps, False)

  def get_comp_child_state(self, template):
    """Return a tuple: the first value describes if a component is enabled
       in one of the child source that matcth the given template. 
       The second value describes if the first value is inconsistent."""
    comps = []
    for child in self.distro.child_sources:
        if child.template == template:
            comps.extend(child.comps)
    if len(comps) > 0 and \
        len(self.distro.enabled_comps ^ set(comps)) == 0:
        # All enabled distro components are also enabled for the child source
        return (True, False)
    elif len(comps) > 0 and\
        len(self.distro.enabled_comps ^ set(comps)) != 0:
        # A matching child source does exist but doesn't include all 
        # enabled distro components
        return(False, True)
    else:
        # There is no corresponding child source at all
        return (False, False)
  
  def reload_sourceslist(self):
    self.sourceslist.refresh()
    self.sourceslist_visible=[]
    self.distro.get_sources(self.sourceslist)    

  def write_config(self):
    """Write the current apt configuration to file"""
    # update the adept file as well if it is there
    conffiles = [self.rootdir+"/etc/apt/apt.conf.d/10periodic",
                 self.rootdir+"/etc/apt/apt.conf.d/20auto-upgrades",
                 self.rootdir+"/etc/apt/apt.conf.d/15adept-periodic-update"]

    # check (beforehand) if one exists, if not create one
    for f in conffiles:
      if os.path.isfile(f):
        break
    else:
      print("No config found, creating one")
      open(conffiles[0], "w")

    # ensure /etc/cron.daily/apt is executable
    ac = "/etc/cron.daily/apt"
    if os.path.exists(ac):
      perm = os.stat(ac)[stat.ST_MODE]
      if not (perm & stat.S_IXUSR):
        print("file '%s' not executable, fixing" % ac)
        os.chmod(ac, 0o755)

    # now update them
    for periodic in conffiles:
      # read the old content first
      content = []
      if os.path.isfile(periodic):
        content = open(periodic, "r").readlines()
        cnf = apt_pkg.config.subtree("APT::Periodic")

        # then write a new file without the updated keys
        f = open(periodic, "w")
        for line in content:
          for key in cnf.list():
            if line.find("APT::Periodic::%s" % (key)) >= 0:
              break
          else:
            f.write(line)

        # and append the updated keys
        for i in cnf.list():
          f.write("APT::Periodic::%s \"%s\";\n" % (i, cnf.find_i(i)))
        f.close()    

  def save_sourceslist(self):
    """Backup the existing sources.list files and write the current 
       configuration"""
    self.sourceslist.backup(".save")
    self.sourceslist.save()

  def _is_line_in_whitelisted_channel(self, srcline):
    """
    helper that checks if a given line is in the source list
    return the channel name or None if not found
    """
    srcentry = SourceEntry(srcline)
    if os.path.exists(self.CHANNEL_PATH):
      for f in glob.glob("%s/*.list" % self.CHANNEL_PATH):
        for line in open(f):
          if line.strip().startswith("#"):
            continue
          if srcentry == SourceEntry(line):
            return os.path.splitext(os.path.basename(f))[0]
    return None

  def check_and_add_key_for_whitelisted_channels(self, srcline):
    # This is maintained for any legacy callers
    return self.check_and_add_key_for_whitelisted_shortcut(shortcut_handler(srcline))

  def check_and_add_key_for_whitelisted_shortcut(self, shortcut):
    """
    helper that adds the gpg key of the channel to the apt
    keyring *if* the channel is in the whitelist
    /usr/share/app-install/channels or it is a public Launchpad PPA.
    """
    (srcline, _fname) = shortcut.expand(
        codename=self.distro.codename, distro=self.distro.id.lower())
    channel = self._is_line_in_whitelisted_channel(srcline)
    if channel:
      keyp = "%s/%s.key" % (self.CHANNEL_PATH, channel)
      self.add_key(keyp)

    cdata = (shortcut.add_key, {'keyserver': (self.options and
                                              self.options.keyserver)})
    def addkey_func():
        func, kwargs = cdata
        func(**kwargs)

    worker = threading.Thread(target=addkey_func)
    worker.start()
    return worker

  def update_interface(self):
    " abstract interface to keep the UI alive "

  def expand_http_line(self, line):
    """
    short cut - this:
      apt-add-repository http://packages.medibuntu.org free non-free
    same as
      apt-add-repository 'deb http://packages.medibuntu.org/ '$(lsb_release -cs)' free non-free'
    """
    if not line.startswith("http"):
      return line
    repo = line.split()[0]
    try:
        areas = line.split(" ",1)[1]
    except IndexError:
        areas = "main"
    line = "deb %s %s %s" % ( repo, self.distro.codename, areas )
    return line

  def add_source_from_line(self, line, enable_source_code=False):
    """
    Add a source for the given line.
    """
    return self.add_source_from_shortcut(
        shortcut=shortcut_handler(line.strip()),
        enable_source_code=enable_source_code)

  def add_source_from_shortcut(self, shortcut, enable_source_code=False):
    """
    Add a source with the given shortcut and add the signing key if the
    site is in whitelist or the shortcut implementer adds it.
    """

    (deb_line, file) = shortcut.expand(
        codename=self.distro.codename, distro=self.distro.id.lower())
    deb_line = self.expand_http_line(deb_line)
    debsrc_entry_type = 'deb-src' if enable_source_code else '# deb-src'
    debsrc_line = debsrc_entry_type + deb_line[3:]
    new_deb_entry = SourceEntry(deb_line, file)
    new_debsrc_entry = SourceEntry(debsrc_line, file)
    if new_deb_entry.invalid or new_debsrc_entry.invalid:
      return False
    worker = self.check_and_add_key_for_whitelisted_shortcut(shortcut)
    self.sourceslist.add(new_deb_entry.type,
                         new_deb_entry.uri,
                         new_deb_entry.dist,
                         new_deb_entry.comps,
                         comment=new_deb_entry.comment,
                         file=new_deb_entry.file,
                         architectures=new_deb_entry.architectures)
    self.sourceslist.add(debsrc_entry_type,
                         new_debsrc_entry.uri,
                         new_debsrc_entry.dist,
                         new_debsrc_entry.comps,
                         comment=new_debsrc_entry.comment,
                         file=new_debsrc_entry.file,
                         architectures=new_debsrc_entry.architectures)
    self.set_modified_sourceslist()
    if worker:
        # wait for GPG key to be downloaded
        worker.join(30)
    if self.options and self.options.update:
        import apt
        cache = apt.Cache()
        cache.update(sources_list=new_debsrc_entry.file)
    return True

  def remove_source(self, source, remove_source_code=True):
    """Remove the given source"""
    if remove_source_code:
      if isinstance(source, str):
        # recall this method giving a SourceEntry as an argument
        source = self._find_source_from_string(source)
        self.remove_source(source, True)
      elif source is not None:
        self.remove_source(source, False)
        # remove the deb-src lines (enabled or not) associated to
        # this source entry
        source = copy.copy(source)
        source.type = 'deb-src'
        source.disabled = True
        self.remove_source(source, False)
        source.disabled = False
        self.remove_source(source, False)
      return

    # first find the source object if we got a string
    if isinstance(source, str):
      source = self._find_source_from_string(source)
    if source is None:
      return
    # if its a sources.list.d file and it contains only a single line
    # (the line that we just remove), then all references to that
    # file are gone and the file is not saved. we work around that
    # here
    if source.file != apt_pkg.config.find_file("Dir::Etc::sourcelist"):
      self.sourceslist.list.append(SourceEntry("", file=source.file))
    try:
      self.sourceslist.remove(source)
    except ValueError:
      # this exception is raised if trying to remove an entry that does
      # not exist. in this case we suppress the error because there's no
      # need to propagate it (the aim of this method is to ensure that
      # the given entries are not listed in the sourceslist)
      pass
    self.set_modified_sourceslist()

  def add_key(self, path):
    """Add a gnupg key to the list of trusted software vendors"""
    if not os.path.exists(path):
        return False
    try:
        res = self.apt_key.add(path)
        self.KeysModified()
        return res
    except:
        return False

  def add_key_from_data(self, keydata):
    "Add a gnupg key from a utf-8 data string (e.g. copy-n-paste)"
    tmp = tempfile.NamedTemporaryFile()
    tmp.write(keydata.encode("utf-8"))
    tmp.flush()
    return self.add_key(tmp.name)

  def remove_key(self, keyid):
    """Remove a gnupg key from the list of trusted software vendors"""
    try:
        self.apt_key.rm(keyid)
        self.KeysModified()
        return True
    except:
        return False

  def update_keys(self):
    """ Run apt-key update """
    try:
      self.apt_key.update()
      self.KeysModified()
      return True
    except:
      return False


def shortcut_handler(shortcut):
    for factory in _SHORTCUT_FACTORIES:
        ret = factory(shortcut)
        if ret is not None:
            return ret

    raise shortcuts.ShortcutException("Unable to handle input '%s'" % shortcut)


if __name__ == "__main__":
  sp = SoftwareProperties()
  print(sp.get_release_upgrades_policy())
  sp.set_release_upgrades_policy(0)