bug 859715 protect against migration failures of social providers, r=markh

toolkit/components/social/SocialService.jsm

@@ -126,20 +126,38 @@ let ActiveProviders = {
 function migrateSettings() {
   let activeProviders;
   try {
-    // we don't care what the value is, if it is set, we've already migrated
     activeProviders = Services.prefs.getCharPref("social.activeProviders");
   } catch(e) {
-    // do nothing
+    // not set, we'll check if we need to migrate older prefs
   }
   if (activeProviders) {
     // migration from fx21 to fx22 or later
     // ensure any *builtin* provider in activeproviders is in user level prefs
     for (let origin in ActiveProviders._providers) {
-      let prefname = getPrefnameFromOrigin(origin);
+      let prefname;
+      try {
+        prefname = getPrefnameFromOrigin(origin);
+      } catch(e) {
+        // Our preference is missing or bad, remove from ActiveProviders and
+        // continue. This is primarily an error-case and should only be
+        // reached by either messing with preferences or hitting the one or
+        // two days of nightly that ran into it, so we'll flush right away.
+        ActiveProviders.delete(origin);
+        ActiveProviders.flush();
+        continue;
+      }
       if (!Services.prefs.prefHasUserValue(prefname)) {
         // if we've got an active *builtin* provider, ensure that the pref
         // is set at a user-level as that will signify *installed* status.
-        let manifest = JSON.parse(Services.prefs.getComplexValue(prefname, Ci.nsISupportsString).data);
+        let manifest;
+        try {
+          manifest = JSON.parse(Services.prefs.getComplexValue(prefname, Ci.nsISupportsString).data);
+        } catch(e) {
+          // see comment in the delete/flush code above.
+          ActiveProviders.delete(origin);
+          ActiveProviders.flush();
+          continue;
+        }
         // our default manifests have been updated with the builtin flags as of
         // fx22, delete it so we can set the user-pref
         delete manifest.builtin;
@@ -167,7 +185,13 @@ function migrateSettings() {
   let prefs = manifestPrefs.getChildList("", []);
   for (let pref of prefs) {
     try {
-      let manifest = JSON.parse(manifestPrefs.getComplexValue(pref, Ci.nsISupportsString).data);
+      let manifest;
+      try {
+        manifest = JSON.parse(manifestPrefs.getComplexValue(pref, Ci.nsISupportsString).data);
+      } catch(e) {
+        // bad or missing preference, we wont update this one.
+        continue;
+      }
       if (manifest && typeof(manifest) == "object" && manifest.origin) {
         // our default manifests have been updated with the builtin flags as of
         // fx22, delete it so we can set the user-pref
@@ -196,7 +220,14 @@ function initService() {
     Services.obs.removeObserver(xpcomShutdown, "xpcom-shutdown");
   }, "xpcom-shutdown", false);
 
-  migrateSettings();
+  try {
+    migrateSettings();
+  } catch(e) {
+    // no matter what, if migration fails we do not want to render social
+    // unusable. Worst case scenario is that, when upgrading Firefox, previously
+    // enabled providers are not migrated.
+    Cu.reportError("Error migrating social settings: " + e);
+  }
   // Initialize the MozSocialAPI
   if (SocialServiceInternal.enabled)
     MozSocialAPI.enabled = true;

toolkit/components/social/test/xpcshell/test_SocialServiceMigration22.js

@@ -26,6 +26,8 @@ function run_test() {
              createInstance(Ci.nsISupportsString);
   let active = {};
   active[manifest.origin] = 1;
+  // bad.origin tests that a missing manifest does not break migration, bug 859715
+  active["bad.origin"] = 1;
   activeVal.data = JSON.stringify(active);
   Services.prefs.setComplexValue("social.activeProviders",
                                  Ci.nsISupportsString, activeVal);
@@ -57,4 +59,7 @@ function testMigration(manifest, next) {
   do_check_true(activeProviders[manifest.origin]);
   do_check_true(MANIFEST_PREFS.prefHasUserValue(manifest.origin));
   do_check_true(JSON.parse(DEFAULT_PREFS.getCharPref(manifest.origin)).builtin);
+
+  // bug 859715, this should have been removed during migration
+  do_check_false(!!activeProviders["bad.origin"]);
 }