Fix game end during dragging

The stale-first-click fix interfered with proper handling of a piece
being dragged when a game suddenly ended (because of opponent resign,
or caling the flag), because up-clicks when the from-square was reset
were completely ignored. Now such an 'unmatched' upclick calls
DragPieceEnd() and redraws the board.

diff --git a/backend.c b/backend.c
index 36a7ea2..84f64e5 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -6266,7 +6266,7 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
 {
     int x, y;
     Boolean saveAnimate;
-    static int second = 0, promotionChoice = 0;
+    static int second = 0, promotionChoice = 0, dragging = 0;
     char promoChoice = NULLCHAR;
 
     if(appData.seekGraph && appData.icsActive && loggedOn &&
@@ -6326,11 +6326,14 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
                fromY = y;
                second = 0;
                MarkTargetSquares(0);
-               DragPieceBegin(xPix, yPix);
+               DragPieceBegin(xPix, yPix); dragging = 1;
                if (appData.highlightDragging) {
                    SetHighlights(x, y, -1, -1);
                }
            }
+       } else if(dragging); { // [HGM] from-square must have been reset due to game end since last press
+           DragPieceEnd(xPix, yPix); dragging = 0;
+           DrawPosition(FALSE, NULL);
        }
        return;
       }
@@ -6367,7 +6370,7 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
            }
            if (OKToStartUserMove(x, y)) {
                fromX = x;
-               fromY = y;
+               fromY = y; dragging = 1;
                MarkTargetSquares(0);
                DragPieceBegin(xPix, yPix);
            }
@@ -6379,7 +6382,7 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
     }
 
     if (clickType == Release && x == fromX && y == fromY) {
-       DragPieceEnd(xPix, yPix);
+       DragPieceEnd(xPix, yPix); dragging = 0;
        if (appData.animateDragging) {
            /* Undo animation damage if any */
            DrawPosition(FALSE, NULL);
@@ -6417,7 +6420,7 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
        } else {
            ClearHighlights();
        }
-       DragPieceEnd(xPix, yPix);
+       DragPieceEnd(xPix, yPix); dragging = 0;
        /* Don't animate move and drag both */
        appData.animate = FALSE;
     }