Fix "command CHECK illegal in state AUTH"

Dave identified a case where our new dropped connection handling did
not work out correctly: we use the retry_left variable to signify
success (0=success if no exception occured).

However, we were decrementing the variable AFTER all the exception
checks, so if there was one due to a dropped connection, it
could well be that we 1) did not raise an exception (because we want to
retry), and 2) then DECREMENTED retry_left, which indicated "all is
well, no need to retry".

The code then continued to check() the append, which failed with the
above message (because we obtained a new connection which had not even
selected the current folder and we were still in mode AUTH). The fix is
of course, to fix our logic: Decrement retry_left first, THEN decide
whether to raise() (retry_left==0) or retry (retry_left>0) which would
then correctly attempt another loop. I am sorry for this newbie type of
logic error. The retry count loop was too hastily slipped in, it seems.

Reported-by: Dave Abrahams <dave@boostpro.com>
Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

offlineimap/folder/IMAP.py

@@ -536,7 +536,7 @@ class IMAPFolder(BaseFolder):
                     retry_left = 0 # Mark as success
                 except imapobj.abort, e:
                     # connection has been reset, release connection and retry.
-                    self.ui.error(e, exc_info()[2])
+                    retry_left -= 1
                     self.imapserver.releaseconnection(imapobj, True)
                     imapobj = self.imapserver.acquireconnection()
                     if not retry_left:
@@ -545,7 +545,8 @@ class IMAPFolder(BaseFolder):
                               "Message content was: %s" %
                               (self, self.getrepository(), str(e), dbg_output),
                                                OfflineImapError.ERROR.MESSAGE)
-                    retry_left -= 1
+                    self.ui.error(e, exc_info()[2])
+
                 except imapobj.error, e: # APPEND failed
                     # If the server responds with 'BAD', append()
                     # raise()s directly.  So we catch that too.