move sanity check to server and automatically force full sync

- server will log mismatches so we don't require people to post on the forums
  anymore or manually force a full sync
- if we find problems like missing notes, report that in the sanity check so
  the server can keep track of problems
- when the server detects a conflict it can immediately abort the sync, so a
  subsequent sync will no longer report a conflict

anki/sync.py

@@ -133,13 +133,16 @@ class Syncer(object):
             self.server.applyChunk(chunk=chunk)
             if chunk['done']:
                 break
-        # step 5: sanity check during beta testing
+        # step 5: sanity check
         runHook("sync", "sanity")
         c = self.sanityCheck()
-        s = self.server.sanityCheck()
+        ret = self.server.sanityCheck2(client=c)
-        if c != s:
+        if ret['status'] != "ok":
-            raise Exception("""\
+            # roll back and force full sync
-Sanity check failed. Please copy and paste the text below:\n%s\n%s""" % (c, s))
+            self.col.rollback()
+            self.col.modSchema()
+            self.col.save()
+            raise Exception("sanity check failed")
         # finalize
         runHook("sync", "finalize")
         mod = self.server.finish()
@@ -179,19 +182,22 @@ Sanity check failed. Please copy and paste the text below:\n%s\n%s""" % (c, s))
         self.prepareToChunk()
 
     def sanityCheck(self):
-        # some basic checks to ensure the sync went ok. this is slow, so will
+        if self.col.db.scalar("""
-        # be removed before official release
+select count() from cards where nid not in (select id from notes)"""):
-        assert not self.col.db.scalar("""
+            return "missing notes"
-select count() from cards where nid not in (select id from notes)""")
+        if self.col.db.scalar("""
-        assert not self.col.db.scalar("""
+select count() from notes where id not in (select distinct nid from cards)"""):
-select count() from notes where id not in (select distinct nid from cards)""")
+            return "missing cards"
         for t in "cards", "notes", "revlog", "graves":
-            assert not self.col.db.scalar(
+            if self.col.db.scalar(
-                "select count() from %s where usn = -1" % t)
+                "select count() from %s where usn = -1" % t):
+                return "%t had usn = -1" % t
         for g in self.col.decks.all():
-            assert g['usn'] != -1
+            if g['usn'] == -1:
+                return "deck had usn = -1"
         for t, usn in self.col.tags.allItems():
-            assert usn != -1
+            if usn == -1:
+                return "tag had usn = -1"
         found = False
         for m in self.col.models.all():
             if self.col.server:
@@ -200,7 +206,8 @@ select count() from notes where id not in (select distinct nid from cards)""")
                     m['usn'] = 0
                     found = True
             else:
-                assert m['usn'] != -1
+                if m['usn'] == -1:
+                    return "model had usn = -1"
         if found:
             self.col.models.save()
         self.col.sched.reset()
@@ -218,6 +225,12 @@ select count() from notes where id not in (select distinct nid from cards)""")
             len(self.col.decks.allConf()),
         ]
 
+    def sanityCheck2(self, client):
+        server = self.sanityCheck()
+        if client != server:
+            return dict(status="bad", c=client, s=server)
+        return dict(status="ok")
+
     def usnLim(self):
         if self.col.server:
             return "usn >= %d" % self.minUsn
@@ -580,8 +593,8 @@ class RemoteServer(HttpSyncer):
     def applyChunk(self, **kw):
         return self._run("applyChunk", kw)
 
-    def sanityCheck(self, **kw):
+    def sanityCheck2(self, **kw):
-        return self._run("sanityCheck", kw)
+        return self._run("sanityCheck2", kw)
 
     def finish(self, **kw):
         return self._run("finish", kw)

aqt/sync.py

@@ -134,6 +134,10 @@ AnkiWeb is too busy at the moment. Please try again in a few minutes.""")
                 "Antivirus or firewall software is preventing Anki from connecting to the internet.")
         elif "407" in err:
             return _("Proxy authentication required.")
+        elif "sanity check failed" in err:
+            return _("After syncing, the collection was in an inconsistent \
+state. To fix this problem, Anki will force a full sync. Please sync again, and \
+choose which side you would like to keep.")
         return err
 
     def _getUserPass(self):