Handle I/O errors better

- Do not crash because of low disk space
- Notify the user whenever it happens
- A few functions now return a boolean instead of nothing
- Config.silent_set is Config.set_and_save without toggle and returning
  strings. It is used whenever we don’t need set_and_save
- Config.set_and_save now returns a tuple (that can be passed directly
  to core.information())

TODO: display the precise error to the user (instead of “unable to…”)

5 files changed, 81 insertions, 35 deletions

diff --git a/src/config.py b/src/config.py
index e3c93f29..c94bb89a 100644
--- a/src/config.py
+++ b/src/config.py
@@ -12,6 +12,8 @@ from/to the config file
 
 DEFSECTION = "Poezio"
 
+from gettext import gettext as _
+
 from configparser import RawConfigParser, NoOptionError, NoSectionError
 from os import environ, makedirs, path
 from shutil import copy2
@@ -171,10 +173,16 @@ class Config(RawConfigParser):
             result_lines.append('%s = %s' % (option, value))
 
 
-        df = open(self.file_name, 'w', encoding='utf-8')
-        for line in result_lines:
-            df.write('%s\n' % line)
-        df.close()
+        try:
+            df = open(self.file_name, 'w', encoding='utf-8')
+            for line in result_lines:
+                df.write('%s\n' % line)
+            df.close()
+        except:
+            success = False
+        else:
+            success = True
+        return success
 
     def set_and_save(self, option, value, section=DEFSECTION):
         """
@@ -191,15 +199,26 @@ class Config(RawConfigParser):
             elif current.lower() == "true":
                 value = "false"
             else:
-                return "Could not toggle option: %s. Current value is %s." % (option, current or "empty")
+                return (_("Could not toggle option: %s. Current value is %s.") % (option, current or _("empty")), 'Warning')
         if self.has_section(section):
             RawConfigParser.set(self, section, option, value)
         else:
             self.add_section(section)
             RawConfigParser.set(self, section, option, value)
-        self.write_in_file(section, option, value)
-        return "%s=%s" % (option, value)
+        if not self.write_in_file(section, option, value):
+            return (_('Unable to write in the config file'), 'Error')
+        return ("%s=%s" % (option, value), 'Info')
 
+    def silent_set(self, option, value, section=DEFSECTION):
+        """
+        Set a value, save, and return True on success and False on failure
+        """
+        if self.has_section(section):
+            RawConfigParser.set(self, section, option, value)
+        else:
+            self.add_section(section)
+            RawConfigParser.set(self, section, option, value)
+        return self.write_in_file(section, option, value)
 
     def set(self, option, value, section=DEFSECTION):
         """
diff --git a/src/core.py b/src/core.py
index 97470b48..68c7f241 100644
--- a/src/core.py
+++ b/src/core.py
@@ -432,8 +432,9 @@ class Core(object):
         """
         Save config in the file just before exit
         """
-        roster.save_to_config_file()
-        config.set_and_save('info_win_height', self.information_win_size, 'var')
+        if not roster.save_to_config_file() or \
+                not config.silent_set('info_win_height', self.information_win_size, 'var'):
+            self.information(_('Unable to write in the config file'), 'Error')
 
     def on_roster_enter_key(self, roster_row):
         """
@@ -595,8 +596,9 @@ class Core(object):
         """
         self.status = Status(show=pres, message=msg)
         if config.get('save_status', 'true').lower() != 'false':
-            config.set_and_save('status', pres if pres else '')
-            config.set_and_save('status_message', msg.replace('\n', '|') if msg else '')
+            if not config.silent_set('status', pres if pres else '') or \
+                    not config.silent_set('status_message', msg.replace('\n', '|') if msg else ''):
+                self.information(_('Unable to write in the config file'), 'Error')
 
     def get_bookmark_nickname(self, room_name):
         """
@@ -1238,7 +1240,8 @@ class Core(object):
         Enable/disable the left panel.
         """
         enabled = config.get('enable_vertical_tab_list', 'false')
-        config.set_and_save('enable_vertical_tab_list', 'false' if enabled == 'true' else 'true')
+        if not config.silent_set('enable_vertical_tab_list', 'false' if enabled == 'true' else 'true'):
+            self.information(_('Unable to write in the config file'), 'Error')
         self.call_for_resize()
 
     def resize_global_information_win(self):
@@ -2051,7 +2054,7 @@ class Core(object):
             path = os.path.expanduser(value)
             self.plugin_manager.on_plugins_conf_dir_change(path)
         self.call_for_resize()
-        self.information(info, "Info")
+        self.information(*info)
 
     def completion_set(self, the_input):
         """Completion for /set"""
@@ -2336,7 +2339,8 @@ class Core(object):
             return self.command_help('bind')
         elif len(args) < 2:
             args.append("")
-        config.set_and_save(args[0], args[1], section='bindings')
+        if not config.silent_set(args[0], args[1], section='bindings'):
+            self.information(_('Unable to write in the config file'), 'Error')
         if args[1]:
             self.information('%s is now bound to %s' % (args[0], args[1]), 'Info')
         else:
@@ -2716,7 +2720,8 @@ class Core(object):
                 conversation.remote_wants_chatstates = True
             else:
                 conversation.remote_wants_chatstates = False
-        logger.log_message(jid.bare, remote_nick, body)
+        if not logger.log_message(jid.bare, remote_nick, body):
+            self.information(_('Unable to write in the log file'), 'Error')
         if 'private' in config.get('beep_on', 'highlight private').split():
             if config.get_by_tabname('disable_beep', 'false', jid.bare, False).lower() != 'true':
                 curses.beep()
@@ -2967,7 +2972,8 @@ class Core(object):
         if 'private' in config.get('beep_on', 'highlight private').split():
             if config.get_by_tabname('disable_beep', 'false', jid.full, False).lower() != 'true':
                 curses.beep()
-        logger.log_message(jid.full.replace('/', '\\'), nick_from, body)
+        if not logger.log_message(jid.full.replace('/', '\\'), nick_from, body):
+            self.information(_('Unable to write in the log file'), 'Error')
         if tab is self.current_tab():
             self.refresh_window()
         else:
@@ -3147,7 +3153,8 @@ class Core(object):
         if presence.match('presence/muc') or presence.xml.find('{http://jabber.org/protocol/muc#user}x'):
             return
         jid = presence['from']
-        logger.log_roster_change(jid.bare, 'got offline')
+        if not logger.log_roster_change(jid.bare, 'got offline'):
+            self.information(_('Unable to write in the log file'), 'Error')
         # If a resource got offline, display the message in the conversation with this
         # precise resource.
         if jid.resource:
@@ -3168,7 +3175,8 @@ class Core(object):
         if contact is None:
             # Todo, handle presence coming from contacts not in roster
             return
-        logger.log_roster_change(jid.bare, 'got online')
+        if not logger.log_roster_change(jid.bare, 'got online'):
+            self.information(_('Unable to write in the log file'), 'Error')
         resource = Resource(jid.full, {
             'priority': presence.get_priority() or 0,
             'status': presence['status'],
@@ -3430,13 +3438,15 @@ class Core(object):
                 if input.value:
                     self.information('Setting new certificate: old: %s, new: %s' % (cert, found_cert), 'Info')
                     log.debug('Setting certificate to %s', found_cert)
-                    config.set_and_save('certificate', found_cert)
+                    if not config.silent_set('certificate', found_cert):
+                        self.information(_('Unable to write in the config file'), 'Error')
                 else:
                     self.information('You refused to validate the certificate. You are now disconnected', 'Info')
                     self.xmpp.disconnect()
         else:
             log.debug('First time. Setting certificate to %s', found_cert)
-            config.set_and_save('certificate', found_cert)
+            if not config.silent_set('certificate', found_cert):
+                self.information(_('Unable to write in the config file'), 'Error')
 
 
 
diff --git a/src/logger.py b/src/logger.py
index 8b4b1d3c..a696137f 100644
--- a/src/logger.py
+++ b/src/logger.py
@@ -32,7 +32,10 @@ class Logger(object):
     def __del__(self):
         for opened_file in self.fds.values():
             if opened_file:
-                opened_file.close()
+                try:
+                    opened_file.close()
+                except: # Can't close? too bad
+                    pass
 
     def reload_all(self):
         """Close and reload all the file handles (on SIGHUP)"""
@@ -106,7 +109,7 @@ class Logger(object):
         else:
             fd = self.check_and_create_log_dir(jid)
         if not fd:
-            return
+            return True
         try:
             msg = clean_text(msg)
             if date is None:
@@ -117,18 +120,26 @@ class Logger(object):
                 fd.write(''.join((str_time, nick, ': ', msg, '\n')))
             else:
                 fd.write(''.join((str_time,  '* ', msg, '\n')))
-        except IOError:
-            pass
+        except:
+            return False
         else:
-            fd.flush()          # TODO do something better here?
+            try:
+                fd.flush()          # TODO do something better here?
+            except:
+                return False
+        return True
 
     def log_roster_change(self, jid, message):
         if not self.roster_logfile:
             try:
                 self.roster_logfile = open(os.path.join(DATA_HOME, 'logs', 'roster.log'), 'a')
             except IOError:
-                return
-        self.roster_logfile.write('%s %s %s\n' % (datetime.now().strftime('%d-%m-%y [%H:%M:%S]'), jid, message))
-        self.roster_logfile.flush()
+                return False
+        try:
+            self.roster_logfile.write('%s %s %s\n' % (datetime.now().strftime('%d-%m-%y [%H:%M:%S]'), jid, message))
+            self.roster_logfile.flush()
+        except:
+            return False
+        return True
 
 logger = Logger()
diff --git a/src/roster.py b/src/roster.py
index 67e81da9..b0f3cf65 100644
--- a/src/roster.py
+++ b/src/roster.py
@@ -141,7 +141,7 @@ class Roster(object):
         folded_groups = ':'.join([group.name for group in self.groups.values()\
                                       if group.folded])
         log.debug('folded:%s\n' %folded_groups)
-        config.set_and_save('folded_roster_groups', folded_groups, 'var')
+        return config.silent_set('folded_roster_groups', folded_groups, 'var')
 
     def get_nb_connected_contacts(self):
         """
diff --git a/src/tabs.py b/src/tabs.py
index bbae6e3d..ef31da67 100644
--- a/src/tabs.py
+++ b/src/tabs.py
@@ -481,7 +481,8 @@ class ChatTab(Tab):
         """
         Log the messages in the archives.
         """
-        logger.log_message(self.name, nickname, txt, date=time)
+        if not logger.log_message(self.name, nickname, txt, date=time):
+            self.core.information(_('Unable to write in the log file'), 'Error')
 
     def add_message(self, txt, time=None, nickname=None, forced_user=None, nick_color=None, identifier=None):
         self._text_buffer.add_message(txt, time=time,
@@ -1696,7 +1697,8 @@ class MucTab(ChatTab):
         to be
         """
         if time is None and self.joined:        # don't log the history messages
-            logger.log_message(self.name, nickname, txt)
+            if not logger.log_message(self.name, nickname, txt):
+                self.core.information(_('Unable to write in the log file'), 'Error')
 
     def do_highlight(self, txt, time, nickname):
         """
@@ -1844,7 +1846,8 @@ class PrivateTab(ChatTab):
         msg = self.core.xmpp.make_message(self.get_name())
         msg['type'] = 'chat'
         msg['body'] = line
-        logger.log_message(self.get_name().replace('/', '\\'), self.own_nick, line)
+        if not logger.log_message(self.get_name().replace('/', '\\'), self.own_nick, line):
+            self.core.information(_('Unable to write in the log file'), 'Error')
         # trigger the event BEFORE looking for colors.
         # This lets a plugin insert \x19xxx} colors, that will
         # be converted in xhtml.
@@ -2722,9 +2725,11 @@ class RosterInfoTab(Tab):
         """
         option = 'roster_show_offline'
         if config.get(option, 'false') == 'false':
-            config.set_and_save(option, 'true')
+            success = config.silent_set(option, 'true')
         else:
-            config.set_and_save(option, 'false')
+            success = config.silent_set(option, 'false')
+        if not success:
+            self.information(_('Unable to write in the config file'), 'Error')
         return True
 
     def on_slash(self):
@@ -3036,7 +3041,8 @@ class ConversationTab(ChatTab):
         self.core.events.trigger('conversation_say_after', msg, self)
         self.last_sent_message = msg
         msg.send()
-        logger.log_message(safeJID(self.get_dest_jid()).bare, self.core.own_nick, line)
+        if not logger.log_message(safeJID(self.get_dest_jid()).bare, self.core.own_nick, line):
+            self.core.information(_('Unable to write in the log file'), 'Error')
         self.cancel_paused_delay()
         self.text_win.refresh()
         self.input.refresh()