[epiphany/gnome-3-26] sync-service: Fix crash when signing out while syncing

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 72aa20dfdc111a7e7e4a298b6ad0fcb39900b58c
Author: Gabriel Ivascu <gabrielivascu gnome org>
Date:   Sun May 6 12:30:48 2018 +0300

    sync-service: Fix crash when signing out while syncing
    
    When the user signs out, all sync secrets including the crypto-keys are
    deleted. If the sign out happens while syncing, i.e. while retrieving
    the sync records from the server, and the server request callback is
    called after the sign out, the sync service will try to access the
    crypto-keys that no longer exist.

 lib/sync/ephy-sync-service.c | 33 +++++++++++++++++++++++++++++----
 1 file changed, 29 insertions(+), 4 deletions(-)
---
diff --git a/lib/sync/ephy-sync-service.c b/lib/sync/ephy-sync-service.c
index 49658e244..1536bcd99 100644
--- a/lib/sync/ephy-sync-service.c
+++ b/lib/sync/ephy-sync-service.c
@@ -401,6 +401,11 @@ ephy_sync_service_get_key_bundle (EphySyncService *self,
   g_assert (collection);
 
   crypto_keys = ephy_sync_service_get_secret (self, secrets[CRYPTO_KEYS]);
+  if (!crypto_keys) {
+    g_warning ("Missing crypto-keys secret");
+    return NULL;
+  }
+
   node = json_from_string (crypto_keys, &error);
   g_assert (!error);
   json = json_node_get_object (node);
@@ -1111,6 +1116,10 @@ ephy_sync_service_delete_synchronizable (EphySyncService           *self,
   g_assert (ephy_sync_utils_user_is_signed_in ());
 
   collection = ephy_synchronizable_manager_get_collection_name (manager);
+  bundle = ephy_sync_service_get_key_bundle (self, collection);
+  if (!bundle)
+    return;
+
   id = ephy_synchronizable_get_id (synchronizable);
   /* Firefox uses UUIDs with curly braces as IDs for saved passwords records.
    * Curly braces are unsafe characters in URLs so they must be encoded.
@@ -1124,7 +1133,6 @@ ephy_sync_service_delete_synchronizable (EphySyncService           *self,
   json_object_set_string_member (object, "id", id);
   json_object_set_boolean_member (object, "deleted", TRUE);
   record = json_to_string (node, FALSE);
-  bundle = ephy_sync_service_get_key_bundle (self, collection);
   payload = ephy_sync_crypto_encrypt_record (record, bundle);
   json_object_remove_member (object, "deleted");
   json_object_set_string_member (object, "payload", payload);
@@ -1172,6 +1180,9 @@ download_synchronizable_cb (SoupSession *session,
   type = ephy_synchronizable_manager_get_synchronizable_type (data->manager);
   collection = ephy_synchronizable_manager_get_collection_name (data->manager);
   bundle = ephy_sync_service_get_key_bundle (data->service, collection);
+  if (!bundle)
+    goto out;
+
   synchronizable = EPHY_SYNCHRONIZABLE (ephy_synchronizable_from_bso (node, type, bundle, &is_deleted));
   if (!synchronizable) {
     g_warning ("Failed to create synchronizable object from BSO");
@@ -1282,6 +1293,9 @@ ephy_sync_service_upload_synchronizable (EphySyncService           *self,
 
   collection = ephy_synchronizable_manager_get_collection_name (manager);
   bundle = ephy_sync_service_get_key_bundle (self, collection);
+  if (!bundle)
+    return;
+
   bso = ephy_synchronizable_to_bso (synchronizable, bundle);
   id = ephy_synchronizable_get_id (synchronizable);
   /* Firefox uses UUIDs with curly braces as IDs for saved passwords records.
@@ -1320,9 +1334,12 @@ ephy_sync_service_split_into_batches (EphySyncService           *self,
   g_assert (EPHY_IS_SYNCHRONIZABLE_MANAGER (manager));
   g_assert (synchronizables);
 
-  batches = g_ptr_array_new_with_free_func (g_free);
   collection = ephy_synchronizable_manager_get_collection_name (manager);
   bundle = ephy_sync_service_get_key_bundle (self, collection);
+  if (!bundle)
+    return NULL;
+
+  batches = g_ptr_array_new_with_free_func (g_free);
 
   for (guint i = start; i < end; i += EPHY_SYNC_BATCH_SIZE) {
     JsonNode *node = json_node_new (JSON_NODE_ARRAY);
@@ -1502,7 +1519,7 @@ sync_collection_cb (SoupSession *session,
 {
   SyncCollectionAsyncData *data = (SyncCollectionAsyncData *)user_data;
   EphySynchronizable *remote;
-  SyncCryptoKeyBundle *bundle;
+  SyncCryptoKeyBundle *bundle = NULL;
   JsonNode *node = NULL;
   JsonArray *array = NULL;
   GError *error = NULL;
@@ -1530,6 +1547,9 @@ sync_collection_cb (SoupSession *session,
 
   type = ephy_synchronizable_manager_get_synchronizable_type (data->manager);
   bundle = ephy_sync_service_get_key_bundle (data->service, collection);
+  if (!bundle)
+    goto out_error;
+
   for (guint i = 0; i < json_array_get_length (array); i++) {
     remote = EPHY_SYNCHRONIZABLE (ephy_synchronizable_from_bso (json_array_get_element (array, i),
                                                                 type, bundle, &is_deleted));
@@ -1559,6 +1579,8 @@ out_error:
     g_signal_emit (data->service, signals[SYNC_FINISHED], 0);
   sync_collection_async_data_free (data);
 out_no_error:
+  if (bundle)
+    ephy_sync_crypto_key_bundle_free (bundle);
   if (node)
     json_node_unref (node);
   if (error)
@@ -1859,6 +1881,10 @@ ephy_sync_service_upload_client_record (EphySyncService *self)
 
   g_assert (EPHY_IS_SYNC_SERVICE (self));
 
+  bundle = ephy_sync_service_get_key_bundle (self, "clients");
+  if (!bundle)
+    return;
+
   /* Make device ID and name. */
   device_bso_id = ephy_sync_utils_get_device_bso_id ();
   device_id = ephy_sync_utils_get_device_id ();
@@ -1866,7 +1892,6 @@ ephy_sync_service_upload_client_record (EphySyncService *self)
 
   /* Make BSO as string. */
   record = ephy_sync_utils_make_client_record (device_bso_id, device_id, device_name);
-  bundle = ephy_sync_service_get_key_bundle (self, "clients");
   encrypted = ephy_sync_crypto_encrypt_record (record, bundle);
 
   bso = json_object_new ();