[util] Make hb-shape continue shaping other lines if shapers failed
diff --git a/util/main-font-text.hh b/util/main-font-text.hh
index 1a9739f..1dbaaff 100644
--- a/util/main-font-text.hh
+++ b/util/main-font-text.hh
@@ -66,7 +66,7 @@
 
     consumer.finish (&font_opts);
 
-    return 0;
+    return consumer.failed ? 1 : 0;
   }
 
   protected: