tweak sync conflict msg

aqt/sync.py

@@ -32,6 +32,7 @@ class SyncManager(QObject):
     def _sync(self, auth=None):
         # to avoid gui widgets being garbage collected in the worker thread,
         # run gc in advance
+        self._didFullUp = False
         gc.collect()
         # create the thread, setup signals and start running
         t = self.thread = SyncThread(
@@ -47,6 +48,14 @@ class SyncManager(QObject):
             self.mw.app.processEvents()
             self.thread.wait(100)
         self.mw.progress.finish()
+        if self._didFullUp:
+            showWarning(_("""\
+Your collection was successfully uploaded to AnkiWeb.
+
+If you use any other devices, please sync them now, and choose \
+to download the collection you have just uploaded from this computer. \
+After doing so, future reviews and added cards will be merged \
+automatically."""))
 
     def _updateLabel(self):
         self.mw.progress.update(label="%s\n%s" % (
@@ -76,6 +85,7 @@ class SyncManager(QObject):
             if t == "login":
                 m = _("Syncing...")
             elif t == "upload":
+                self._didFullUp = True
                 m = _("Uploading to AnkiWeb...")
             elif t == "download":
                 m = _("Downloading from AnkiWeb...")
@@ -190,8 +200,16 @@ Your decks here and on AnkiWeb differ in such a way that they can't \
 be merged together, so it's necessary to overwrite the decks on one \
 side with the decks from the other.
 
-Do you want to upload the decks from here, or download the decks \
+If you choose download, Anki will download the collection from AnkiWeb, \
-from AnkiWeb?"""),
+and any changes you have made on your computer since the last sync will \
+be lost.
+
+If you choose upload, Anki will upload your collection to AnkiWeb, and \
+any changes you have made on AnkiWeb or your other devices since the \
+last sync to this device will be lost.
+
+After all devices are in sync, future reviews and added cards can be merged
+automatically."""),
                 [_("Upload to AnkiWeb"),
                  _("Download from AnkiWeb"),
                  _("Cancel")])