--- a/mercurial/cext/revlog.c	Wed Jun 13 14:28:39 2018 -0700
+++ b/mercurial/cext/revlog.c	Thu Jun 14 20:09:54 2018 +0900
@@ -333,10 +333,8 @@
 		PyMem_Free(self->offsets);
 		self->offsets = NULL;
 	}
-	if (self->nt) {
-		free(self->nt);
-		self->nt = NULL;
-	}
+	free(self->nt);
+	self->nt = NULL;
 	Py_CLEAR(self->headrevs);
 }