fix: when called with -a, mbnames must not erase entries of other accounts

Make mbnames to work with intermediate files, one per account, in the JSON
format. The mbnames target is built from those intermediate files.

Github-Fix: https://github.com/OfflineIMAP/offlineimap/issues/66
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap/init.py

@@ -25,8 +25,7 @@ import logging
 from optparse import OptionParser
 
 import offlineimap
-from offlineimap import accounts, threadutil, folder
-from offlineimap import globals
+from offlineimap import globals, accounts, threadutil, folder, mbnames
 from offlineimap.ui import UI_LIST, setglobalui, getglobalui
 from offlineimap.CustomConfig import CustomConfigParser
 from offlineimap.utils import stacktrace
@@ -423,7 +422,7 @@ class OfflineImap(object):
             signal.signal(signal.SIGQUIT, sig_handler)
 
             # Various initializations that need to be performed:
-            offlineimap.mbnames.init(self.config, syncaccounts)
+            mbnames.init(self.config, self.ui, options.dryrun)
 
             if options.singlethreading:
                 # Singlethreaded.
@@ -440,9 +439,8 @@ class OfflineImap(object):
                 t.start()
                 threadutil.monitor()
 
-            if not options.dryrun:
-                offlineimap.mbnames.write(True)
-
+            # All sync are done.
+            mbnames.write()
             self.ui.terminate()
             return 0
         except (SystemExit):