Bug 1349703 - (part 1) Fix issue where sync would fail misreconcile special folders in fresh syncs r=kitcambridge

MozReview-Commit-ID: Izy9JgMYpom

--HG--
extra : rebase_source : b740e81aafbabae2947fd26888c677065742db96

services/sync/modules/engines.js

@@ -1360,6 +1360,13 @@ SyncEngine.prototype = {
     // By default, assume there's no dupe items for the engine
   },
 
+  /**
+   * Called before a remote record is discarded due to failed reconciliation.
+   * Used by bookmark sync to note the child ordering of special folders.
+   */
+  beforeRecordDiscard(record) {
+  },
+
   // Called when the server has a record marked as deleted, but locally we've
   // changed it more recently than the deletion. If we return false, the
   // record will be deleted locally. If we return true, we'll reupload the
@@ -1569,6 +1576,9 @@ SyncEngine.prototype = {
     // opportunity to merge the records. Bug 720592 tracks this feature.
     this._log.warn("DATA LOSS: Both local and remote changes to record: " +
                    item.id);
+    if (!remoteIsNewer) {
+      this.beforeRecordDiscard(item);
+    }
     return remoteIsNewer;
   },
 

services/sync/modules/engines/bookmarks.js

@@ -630,6 +630,17 @@ BookmarksEngine.prototype = {
            FORBIDDEN_INCOMING_PARENT_IDS.includes(incomingItem.parentid);
   },
 
+  beforeRecordDiscard(record) {
+    let isSpecial = PlacesSyncUtils.bookmarks.ROOTS.includes(record.id);
+    if (isSpecial && record.children && !this._store._childrenToOrder[record.id]) {
+      if (this._modified.getStatus(record.id) != PlacesUtils.bookmarks.SYNC_STATUS.NEW) {
+        return;
+      }
+      this._log.debug("Recording children of " + record.id + " as " + JSON.stringify(record.children));
+      this._store._childrenToOrder[record.id] = record.children;
+    }
+  },
+
   getValidator() {
     return new BookmarkValidator();
   }
@@ -1122,6 +1133,14 @@ class BookmarksChangeset extends Changeset {
     this.weakChanges = {};
   }
 
+  getStatus(id) {
+    let change = this.changes[id];
+    if (!change) {
+      return PlacesUtils.bookmarks.SYNC_STATUS.UNKNOWN;
+    }
+    return change.status;
+  }
+
   getModifiedTimestamp(id) {
     let change = this.changes[id];
     if (change) {