[telepathy-sasl-signon] Only trigger CredentialsNeedUpdate for specif…

…ic SASL errors

Unfortunately, telepathy's AuthenticationFailed error arrives for many
normal cases, like a connection reset during authentication. We cannot
invalidate credentials indiscriminately.

Instead, watch for the two specific wocky errors that indicate the
server probably rejected our credentials and signal only for those.

telepathy-sasl-signon/empathy-uoa-auth-handler.c

@@ -200,10 +200,23 @@ auth_cb (GObject *source,
   if (!empathy_sasl_auth_finish (channel, result, &error))
     {
       DEBUG ("SASL Mechanism error: %s", error->message);
-      g_clear_error (&error);
 
+      // If the error looks like credential failure, set the CredentialsNeedUpdate flag.
+      // We cannot set the flag for all SASL errors, because this includes things like a
+      // connection reset during authentication.
+      if (strstr(error->message, "WOCKY_AUTH_ERROR_FAILURE") ||
+          strstr(error->message, "WOCKY_AUTH_ERROR_NOT_AUTHORIZED"))
+        {
           request_password (ctx);
         }
+      else
+        {
+          DEBUG ("Auth on %s failed", tp_proxy_get_object_path (channel));
+          auth_context_done (ctx);
+        }
+
+      g_clear_error (&error);
+    }
   else
     {
       DEBUG ("Auth on %s suceeded", tp_proxy_get_object_path (channel));