From: Benjamin Auder <benjamin.auder@somewhere>
Date: Wed, 20 Jan 2021 17:45:35 +0000 (+0100)
Subject: [Otage] fix black pawn promoting with white pawn in hostage
X-Git-Url: https://git.auder.net/%7B%7B%20asset%28%27mixstore/css/img/doc/pieces/cp.svg?a=commitdiff_plain;h=259035ec507062fdfc7158ac62b68c722404bfdf;p=vchess.git

[Otage] fix black pawn promoting with white pawn in hostage
---

diff --git a/client/src/variants/Otage.js b/client/src/variants/Otage.js
index 6c2b1ec0..9eb900a4 100644
--- a/client/src/variants/Otage.js
+++ b/client/src/variants/Otage.js
@@ -255,7 +255,14 @@ export class OtageRules extends ChessRules {
       // Transformation computed without taking union into account
       const up = this.getUnionPieces(initColor, initPiece);
       let args = [tr.p, up[oppCol]];
-      if (['a', 'v'].includes(initColor)) args = args.reverse();
+      if (
+        ['a', 'v'].includes(initColor) ||
+        // HACK: "ba" piece = two pawns, black controling.
+        // If promoting, must artificially imagine color was 'a':
+        (initPiece == 'a' && initColor == 'b')
+      ) {
+        args = args.reverse();
+      }
       const capturer = (['a', 'b'].includes(initColor) ? 'b' : 'w');
       const cp = this.getUnionCode(args[0], args[1], capturer);
       tr.c = cp.c;