From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Sun, 22 Dec 2013 10:48:26 +0000 (+0100)
Subject: Clear memory of erased position on variant switch
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=266cb250971712515fd6dc3e6701779a6036ce1f;p=xboard.git

Clear memory of erased position on variant switch

The Edit Position clear-board cycle would go from initial position to
last-erased position (if this is different), but the latter could have been
from another variant. In wich case we also want to clear.
  also print a message to alert people to the fact that they can click the
clock again to restore the position.
---

diff --git a/backend.c b/backend.c
index aea15b5..6dae63d 100644
--- a/backend.c
+++ b/backend.c
@@ -14593,7 +14593,8 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 {
     char buf[MSG_SIZ];
     ChessSquare piece = boards[0][y][x];
-    static Board erasedBoard, currentBoard, menuBoard;
+    static Board erasedBoard, currentBoard, menuBoard, nullBoard;
+    static int lastVariant;
 
     if (gameMode != EditPosition && gameMode != IcsExamining) return;
 
@@ -14632,13 +14633,16 @@ EditPositionMenuEvent (ChessSquare selection, int x, int y)
 		    p = menuBoard[BOARD_HEIGHT-1][x];
 		    for(y = x + 1; y < BOARD_RGHT; y++) if(menuBoard[BOARD_HEIGHT-1][y] == p) menuBoard[BOARD_HEIGHT-1][y] = EmptySquare;
 		}
+		DisplayMessage("Clicking clock again restores position", "");
+		if(gameInfo.variant != lastVariant) lastVariant = gameInfo.variant, CopyBoard(erasedBoard, boards[0]);
 		if(!nonEmpty) { // asked to clear an empty board
 		    CopyBoard(boards[0], menuBoard);
 		} else
 		if(CompareBoards(currentBoard, menuBoard)) { // asked to clear an empty board
 		    CopyBoard(boards[0], initialPosition);
 		} else
-		if(CompareBoards(currentBoard, initialPosition) && !CompareBoards(currentBoard, erasedBoard)) {
+		if(CompareBoards(currentBoard, initialPosition) && !CompareBoards(currentBoard, erasedBoard)
+								 && !CompareBoards(nullBoard, erasedBoard)) {
 		    CopyBoard(boards[0], erasedBoard);
 		} else
 		    CopyBoard(erasedBoard, currentBoard);