Remove Gmail realdelete option

It can lead to potential dataloss (see recent commit log where I added a
scary warning about it to offlineimap.conf).

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

offlineimap.conf

@@ -531,21 +531,6 @@ type = Gmail
 # Specify the Gmail user name. This is the only mandatory parameter.
 remoteuser = username@gmail.com
 
-# WARNING: READ THIS BEFORE CONSIDERING TO CHANGE IT!  Deleting a
-# message from a Gmail folder via the IMAP interface will just remove
-# that folder's label from the message: the message will continue to
-# exist in the '[Gmail]/All Mail' folder.  If `realdelete` is set to
-# `True`, then deleted messages will be moved to the '[Gmail]/Trash'
-# folder.  BEWARE: this will immediately delete a messages from *all
-# folders* it belongs to! AS OFFLINEIMAP IMPLEMENTS FOLDER MOVES AS 1)
-# AN ADD and 2) A DELETE (the order can vary), THIS MEANS THAT A FOLDER
-# MOVE CAN CAUSE DATALOSS. DO NOT USE IT AND MOVE MAIL TO
-# "[Gmail]/Trash" TO DELETE MAIL FROM "[Gmail]/All Mail"!  See the
-# analysis at
-# http://article.gmane.org/gmane.mail.imap.offlineimap.general/5265 See
-# http://mail.google.com/support/bin/answer.py?answer=77657&topic=12815
-# realdelete = no !!!READ ABOVE BEFORE USING
-
 # The trash folder name may be different from [Gmail]/Trash
 # for example on german googlemail, this setting should be
 #

offlineimap/folder/Gmail.py

@@ -18,16 +18,18 @@
 
 """Folder implementation to support features of the Gmail IMAP server.
 """
-
 from IMAP import IMAPFolder
-from offlineimap import imaputil
-
 
 class GmailFolder(IMAPFolder):
     """Folder implementation to support features of the Gmail IMAP server.
-    Specifically, deleted messages are moved to folder `Gmail.TRASH_FOLDER`
+
-    (by default: ``[Gmail]/Trash``) prior to expunging them, since
+    Removing a message from a folder will only remove the "label" from
-    Gmail maps to IMAP ``EXPUNGE`` command to "remove label".
+    the message and keep it in the "All mails" folder. To really delete
+    a message it needs to be copied to the Trash folder. However, this
+    is dangerous as our folder moves are implemented as a 1) delete in
+    one folder and 2) append to the other. If 2 comes before 1, this
+    will effectively delete the message from all folders. So we cannot
+    do that until we have a smarter folder move mechanism.
 
     For more information on the Gmail IMAP server:
       http://mail.google.com/support/bin/answer.py?answer=77657&topic=12815
@@ -35,31 +37,6 @@ class GmailFolder(IMAPFolder):
 
     def __init__(self, imapserver, name, repository):
         super(GmailFolder, self).__init__(imapserver, name, repository)
-        self.realdelete = repository.getrealdelete(name)
         self.trash_folder = repository.gettrashfolder(name)
-        #: Gmail will really delete messages upon EXPUNGE in these folders
+        # Gmail will really delete messages upon EXPUNGE in these folders
         self.real_delete_folders =  [ self.trash_folder, repository.getspamfolder() ]
-
-    def deletemessages_noconvert(self, uidlist):
-        uidlist = [uid for uid in uidlist if uid in self.messagelist]
-        if not len(uidlist):
-            return
-
-        if self.realdelete and not (self.getname() in self.real_delete_folders):
-            # IMAP expunge is just "remove label" in this folder,
-            # so map the request into a "move into Trash"
-
-            imapobj = self.imapserver.acquireconnection()
-            try:
-                imapobj.select(self.getfullname())
-                result = imapobj.uid('copy',
-                                     imaputil.uid_sequence(uidlist),
-                                     self.trash_folder)
-                assert result[0] == 'OK', \
-                       "Bad IMAPlib result: %s" % result[0]
-            finally:
-                self.imapserver.releaseconnection(imapobj)
-            for uid in uidlist:
-                del self.messagelist[uid]
-        else:
-            IMAPFolder.deletemessages_noconvert(self, uidlist)

offlineimap/repository/Gmail.py

@@ -64,11 +64,6 @@ class GmailRepository(IMAPRepository):
     def getfoldertype(self):
         return folder.Gmail.GmailFolder
 
-    def getrealdelete(self, foldername):
-        # XXX: `foldername` is currently ignored - the `realdelete`
-        # setting is repository-wide
-        return self.getconfboolean('realdelete', 0)
-
     def gettrashfolder(self, foldername):
         #: Where deleted mail should be moved
         return  self.getconf('trashfolder','[Gmail]/Trash')