Fennec now launches first run page, and updates extensions.weave.lastversion, so that it's no longer resetting syncId and therefore resetting the server every single time it tries to sync. Also set the download in resource.js to use LOAD_BYPASS_CACHE. Together these changes seem to fix bug 480270.

services/sync/modules/engines/clients.js

@@ -105,7 +105,9 @@ ClientEngine.prototype = {
   },
 
   get syncID() {
-    if (!Svc.Prefs.get("client.syncID"))
+    let oldSyncId = Svc.Prefs.get("client.syncID");
+    dump("oldSyncId is " + oldSyncId + "\n");
+    if (!oldSyncId)
       Svc.Prefs.set("client.syncID", Utils.makeGUID());
     return Svc.Prefs.get("client.syncID");
   },

services/sync/modules/resource.js

@@ -151,7 +151,7 @@ Resource.prototype = {
       QueryInterface(Ci.nsIRequest);
     // Always validate the cache:
     let loadFlags = this._lastChannel.loadFlags;
-    loadFlags |= Ci.nsIRequest.VALIDATE_ALWAYS;
+    loadFlags |= Ci.nsIRequest.LOAD_BYPASS_CACHE; //VALIDATE_ALWAYS;
     this._lastChannel.loadFlags = loadFlags;
     this._lastChannel = this._lastChannel.QueryInterface(Ci.nsIHttpChannel);
 

services/sync/modules/service.js

@@ -578,6 +578,7 @@ WeaveSvc.prototype = {
     this._log.debug("Fetching global metadata record");
     let meta = yield Records.import(self.cb, this.clusterURL +
 				    this.username + "/meta/global");
+
     let remoteVersion = (meta && meta.payload.storageVersion)?
       meta.payload.storageVersion : "";
 
@@ -623,6 +624,8 @@ WeaveSvc.prototype = {
       return;
 
     } else if (meta.payload.syncID != Clients.syncID) {
+      this._log.warn("Meta.payload.syncID is " + meta.payload.syncID);
+      this._log.warn(", Clients.syncID is " + Clients.syncID);
       yield this.resetClient(self.cb);
       this._log.info("Reset client because of syncID mismatch.");
       Clients.syncID = meta.payload.syncID;

services/sync/services-sync.js

@@ -36,3 +36,4 @@ pref("extensions.weave.log.logger.engine.tabs", "Debug");
 pref("extensions.weave.log.logger.engine.clients", "Debug");
 
 pref("extensions.weave.network.numRetries", 2);
+pref("extensions.weave.client.syncID", "YOUR MOM");