Bug 1273341 - Don't attempt to sync tabs with very long URLs. r=markh

Now with a test.

MozReview-Commit-ID: 9QehGKLbqLA

--HG--
extra : amend_source : 412b4b8b1efaf0797ee2272cacbb122e1b18918f

services/sync/modules/engines/tabs.js

@@ -165,6 +165,11 @@ TabStore.prototype = {
           continue;
         }
 
+        if (current.url.length >= (MAX_UPLOAD_BYTES - 1000)) {
+          this._log.trace("Skipping over-long URL.");
+          continue;
+        }
+
         // The element at `index` is the current page. Previous URLs were
         // previously visited URLs; subsequent URLs are in the 'forward' stack,
         // which we can't represent in Sync, so we truncate here.

services/sync/tests/unit/test_tab_engine.js

@@ -1,6 +1,7 @@
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
 
+Cu.import("resource://services-sync/constants.js");
 Cu.import("resource://services-sync/engines/tabs.js");
 Cu.import("resource://services-sync/record.js");
 Cu.import("resource://services-sync/service.js");
@@ -23,11 +24,12 @@ add_test(function test_getOpenURLs() {
   _("Test getOpenURLs.");
   let [engine, store] = getMocks();
 
-  let urls = ["http://bar.com", "http://foo.com", "http://foobar.com"];
-  function threeURLs() {
+  let superLongURL = "http://" + (new Array(MAX_UPLOAD_BYTES).join("w")) + ".com/";
+  let urls = ["http://bar.com", "http://foo.com", "http://foobar.com", superLongURL];
+  function fourURLs() {
     return urls.pop();
   }
-  store.getWindowEnumerator = mockGetWindowEnumerator.bind(this, threeURLs, 1, 3);
+  store.getWindowEnumerator = mockGetWindowEnumerator.bind(this, fourURLs, 1, 4);
 
   let matches;
 
@@ -40,6 +42,10 @@ add_test(function test_getOpenURLs() {
   matches = openurlsset.has("http://barfoo.com");
   ok(!matches);
 
+  _("  test matching works (too long)");
+  matches = openurlsset.has(superLongURL);
+  ok(!matches);
+
   run_next_test();
 });