X-Git-Url: http://winboard.nl/cgi-bin?a=blobdiff_plain;f=backend.c;h=677e21cfb47bcb97df4eb98217e59cf5d5237f56;hb=a7db862b2f44d23b358a1319cd8a374cf88c24fd;hp=b1df1978f1fe0d1bbc0ab33f9eea22d81aefddf5;hpb=d39b0224115daf24fa2608e27d0ca16c8cd4aa70;p=xboard.git

diff --git a/backend.c b/backend.c
index b1df197..677e21c 100644
--- a/backend.c
+++ b/backend.c
@@ -6445,7 +6445,7 @@ 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, clearFlag = 0;
     char promoChoice = NULLCHAR;
     ChessSquare piece;
 
@@ -6541,7 +6541,7 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
 		if (appData.highlightDragging) {
 		    SetHighlights(fromX, fromY, -1, -1);
 		}
-	    }
+	    } else fromX = fromY = -1;
 	    return;
 	}
     }
@@ -6602,6 +6602,14 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
 
     if (clickType == Release && x == fromX && y == fromY) {
 	DragPieceEnd(xPix, yPix); dragging = 0;
+	if(clearFlag) {
+	    // a deferred attempt to click-click move an empty square on top of a piece
+	    boards[currentMove][y][x] = EmptySquare;
+	    ClearHighlights();
+	    DrawPosition(FALSE, boards[currentMove]);
+	    fromX = fromY = -1; clearFlag = 0;
+	    return;
+	}
 	if (appData.animateDragging) {
 	    /* Undo animation damage if any */
 	    DrawPosition(FALSE, NULL);
@@ -6621,12 +6629,20 @@ void LeftClick(ClickType clickType, int xPix, int yPix)
 	return;
     }
 
+    clearFlag = 0;
+
     /* we now have a different from- and (possibly off-board) to-square */
     /* Completed move */
     toX = x;
     toY = y;
     saveAnimate = appData.animate;
     if (clickType == Press) {
+	if(gameMode == EditPosition && boards[currentMove][fromY][fromX] == EmptySquare) {
+	    // must be Edit Position mode with empty-square selected
+	    fromX = x; fromY = y; DragPieceBegin(xPix, yPix); dragging = 1; // consider this a new attempt to drag
+	    if(x >= BOARD_LEFT && x < BOARD_RGHT) clearFlag = 1; // and defer click-click move of empty-square to up-click
+	    return;
+	}
 	/* Finish clickclick move */
 	if (appData.animate || appData.highlightLastMove) {
 	    SetHighlights(fromX, fromY, toX, toY);
@@ -12068,6 +12084,7 @@ TwoMachinesEvent P((void))
     char buf[MSG_SIZ];
     ChessProgramState *onmove;
     char *bookHit = NULL;
+    static int stalling = 0;
 
     if (appData.noChessProgram) return;
 
@@ -12104,13 +12121,23 @@ TwoMachinesEvent P((void))
     ResurrectChessProgram();	/* in case first program isn't running */
 
     if(WaitForSecond(TwoMachinesEventIfReady)) return;
-    DisplayMessage("", "");
-    InitChessProgram(&second, FALSE);
-    SendToProgram("force\n", &second);
     if(first.lastPing != first.lastPong) { // [HGM] wait till we are sure first engine has set up position
+      DisplayMessage("", _("Waiting for first chess program"));
       ScheduleDelayedEvent(TwoMachinesEvent, 10);
       return;
     }
+    if(!stalling) {
+      InitChessProgram(&second, FALSE);
+      SendToProgram("force\n", &second);
+    }
+    if(second.lastPing != second.lastPong) { // [HGM] second engine might have to reallocate hash
+      if(!stalling) DisplayMessage("", _("Waiting for second chess program"));
+      stalling = 1;
+      ScheduleDelayedEvent(TwoMachinesEvent, 10);
+      return;
+    }
+    stalling = 0;
+    DisplayMessage("", "");
     if (startedFromSetupPosition) {
 	SendBoard(&second, backwardMostMove);
     if (appData.debugMode) {