Fix disappearance of premoved piece

When a premove was done by dragging, (which for expected recaptures would
be the only way, as click-click moving selects the intended target),
the moved piece would disappear from view. This because the from-square
would not be redrawn (in normal move execution it would remain empty).
This could have been an XBoard-only problem. In any case We now force a
complete redraw of the board, which is not very elegant, but should always
fix it.

diff --git a/backend.c b/backend.c
index 0624dac..7243ee7 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -7051,6 +7051,7 @@ UserMoveEvent (int fromX, int fromY, int toX, int toY, int promoChar)
                            "fromY %d, toX %d, toY %d\n",
                            fromX, fromY, toX, toY);
            }
+            DrawPosition(TRUE, boards[currentMove]); // [HGM] repair animation damage done by premove (in particular emptying from-square)
             return;
        }
        break;
@@ -7072,6 +7073,7 @@ UserMoveEvent (int fromX, int fromY, int toX, int toY, int promoChar)
                            "fromY %d, toX %d, toY %d\n",
                            fromX, fromY, toX, toY);
            }
+            DrawPosition(TRUE, boards[currentMove]);
             return;
        }
        break;