Do not create folders on readonly repositories

1) Rename the unintuitive repository.syncfoldersto() to
sync_folder_structure()

2) We were checking if the local repository is readonly and then turning
off any folder creation. But as we can create folders on a remote
repository too, we need to be more fine grained here. Just don't create
a folder on the repository that is marked readonly=True.

This still does not do away with the error message that one currently
gets on missing local folders.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

offlineimap/accounts.py

@@ -289,10 +289,10 @@ class SyncableAccount(Account):
             localrepos.getfolders()
             statusrepos.getfolders()
 
+            remoterepos.sync_folder_structure(localrepos, statusrepos)
             # replicate the folderstructure between REMOTE to LOCAL
             if not localrepos.getconfboolean('readonly', False):
                 self.ui.syncfolders(remoterepos, localrepos)
-                remoterepos.syncfoldersto(localrepos, statusrepos)
 
             # iterate through all folders on the remote repo and sync
             for remotefolder in remoterepos.getfolders():

offlineimap/repository/Base.py

@@ -132,8 +132,8 @@ class BaseRepository(object, CustomConfig.ConfigHelperMixin):
 
     def getfolder(self, foldername):
         raise NotImplementedError
-    
-    def syncfoldersto(self, dst_repo, status_repo):
+
+    def sync_folder_structure(self, dst_repo, status_repo):
         """Syncs the folders in this repository to those in dest.
 
         It does NOT sync the contents of those folders. nametrans rules
@@ -158,6 +158,9 @@ class BaseRepository(object, CustomConfig.ConfigHelperMixin):
 
         # Find new folders on src_repo.
         for src_name, src_folder in src_hash.iteritems():
+            # Don't create on dst_repo, if it is readonly
+            if dst_repo.getconfboolean('readonly', False):
+                break
             if src_folder.sync_this and not src_name in dst_hash:
                 try:
                     dst_repo.makefolder(src_name)
@@ -171,6 +174,10 @@ class BaseRepository(object, CustomConfig.ConfigHelperMixin):
                                                    status_repo.getsep()))
         # Find new folders on dst_repo.
         for dst_name, dst_folder in dst_hash.iteritems():
+            if self.getconfboolean('readonly', False):
+                # Don't create missing folder on readonly repo.
+                break
+
             if dst_folder.sync_this and not dst_name in src_hash:
                 # nametrans sanity check!
                 # Does nametrans back&forth lead to identical names?
@@ -202,7 +209,6 @@ class BaseRepository(object, CustomConfig.ConfigHelperMixin):
                                          src_repo, newdst_name),
                                            OfflineImapError.ERROR.REPO)
                 # end sanity check, actually create the folder
-
                 try:
                     src_repo.makefolder(newsrc_name)
                     src_haschanged = True # Need to refresh list