Don't abort on input

src/core/lib/channel/connected_channel.c

@@ -128,7 +128,9 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
 static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
                                  grpc_channel_element *elem) {
   channel_data *cd = (channel_data *)elem->channel_data;
-  grpc_transport_destroy(exec_ctx, cd->transport);
+  if (cd->transport) {
+    grpc_transport_destroy(exec_ctx, cd->transport);
+  }
 }
 
 static char *con_get_peer(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {

src/core/lib/security/transport/client_auth_filter.c

@@ -343,8 +343,16 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
                                      grpc_channel_element_args *args) {
   grpc_security_connector *sc =
       grpc_security_connector_find_in_args(args->channel_args);
+  if (sc == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Security connector missing from client auth filter args");
+  }
   grpc_auth_context *auth_context =
       grpc_find_auth_context_in_args(args->channel_args);
+  if (auth_context == NULL) {
+    return GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Auth context missing from client auth filter args");
+  }
 
   /* grab pointers to our data from the channel element */
   channel_data *chand = elem->channel_data;
@@ -353,8 +361,6 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
      handle the case that there's no 'next' filter to call on the up or down
      path */
   GPR_ASSERT(!args->is_last);
-  GPR_ASSERT(sc != NULL);
-  GPR_ASSERT(auth_context != NULL);
 
   /* initialize members */
   chand->security_connector =