[epiphany/mcatanzaro/passwords-never-work: 1/2] password-manager: fix password saving if multiple passwords exist

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 3fbde829341c20cad2288bffc0959b376bb0bb4c
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Fri Jan 31 16:52:35 2020 -0600

    password-manager: fix password saving if multiple passwords exist
    
    If somehow we already have duplicate passwords saved in the password
    manager, let's deduplicate them instead of giving up. I'm not sure how
    it can get into this state, but it's hardly fatal and it's happening in
    practice.
    
    Note this should be the only query in the file that can unexpectedly
    return multiple results, because other queries that expect to receive
    only a single result are including the record ID in the search.

 lib/sync/ephy-password-manager.c | 41 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)
---
diff --git a/lib/sync/ephy-password-manager.c b/lib/sync/ephy-password-manager.c
index fd5512a78..fa81ea190 100644
--- a/lib/sync/ephy-password-manager.c
+++ b/lib/sync/ephy-password-manager.c
@@ -55,6 +55,10 @@ struct _EphyPasswordManager {
   GHashTable *cache;
 };
 
+static void ephy_password_manager_forget_record (EphyPasswordManager *self,
+                                                 EphyPasswordRecord  *record,
+                                                 EphyPasswordRecord  *replacement);
+
 static void ephy_synchronizable_manager_iface_init (EphySynchronizableManagerInterface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (EphyPasswordManager, ephy_password_manager, G_TYPE_OBJECT,
@@ -434,6 +438,30 @@ ephy_password_manager_store_record (EphyPasswordManager *self,
   g_hash_table_unref (attributes);
 }
 
+static GList *
+deduplicate_records (EphyPasswordManager *manager,
+                     GList               *records)
+{
+  GList *newest = records;
+  guint64 newest_modified = ephy_password_record_get_time_password_changed (newest->data);
+
+  for (GList *l = records->next; l; l = l->next) {
+    guint64 modified = ephy_password_record_get_time_password_changed (l->data);
+    if (modified > newest_modified) {
+      newest = l;
+      newest_modified = modified;
+    }
+  }
+
+  records = g_list_remove_link (records, newest);
+
+  for (GList *l = records; l; l = l->next)
+    ephy_password_manager_forget_record (manager, l->data, NULL);
+  g_list_free_full (records, g_object_unref);
+
+  return newest;
+}
+
 static void
 update_password_cb (GList    *records,
                     gpointer  user_data)
@@ -441,17 +469,20 @@ update_password_cb (GList    *records,
   UpdatePasswordAsyncData *data = (UpdatePasswordAsyncData *)user_data;
   EphyPasswordRecord *record;
 
-  /* We expect only one matching record here. */
-  if (g_list_length (records) == 1) {
+  /* Since we didn't include ID in our query, there could be multiple records
+   * returned. We only want to have one saved at a time, so delete the rest.
+   */
+  if (g_list_length (records) > 1)
+    records = deduplicate_records (data->manager, records);
+
+  if (records) {
     record = EPHY_PASSWORD_RECORD (records->data);
     ephy_password_record_set_password (record, data->password);
     ephy_password_manager_store_record (data->manager, record);
     g_signal_emit_by_name (data->manager, "synchronizable-modified", record, FALSE);
-  } else {
-    g_warn_if_reached ();
+    g_list_free_full (records, g_object_unref);
   }
 
-  g_list_free_full (records, g_object_unref);
   update_password_async_data_free (data);
 }