X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=client%2Fsrc%2Fvariants%2FCheckered.js;fp=client%2Fsrc%2Fvariants%2FCheckered.js;h=ecf25817e7251b44c628f44729af17d2f1cb3081;hb=616561273f216debfeab7f5fc532d0b0a8bc8e2d;hp=79ea63c44a3fc6bd24b71aebf4d2511031d41d12;hpb=0a9cef131612079e55714f56f1466b4e2bd749af;p=vchess.git

diff --git a/client/src/variants/Checkered.js b/client/src/variants/Checkered.js
index 79ea63c4..ecf25817 100644
--- a/client/src/variants/Checkered.js
+++ b/client/src/variants/Checkered.js
@@ -177,7 +177,7 @@ export class CheckeredRules extends ChessRules {
   // Does m2 un-do m1 ? (to disallow undoing checkered moves)
   oppositeMoves(m1, m2) {
     return (
-      m1 &&
+      !!m1 &&
       m2.appear[0].c == "c" &&
       m2.appear.length == 1 &&
       m2.vanish.length == 1 &&