fix for bug #8847: moving backward while examining on FICS not reported to engine

[xboard.git] / backend.c

diff --git a/backend.c b/backend.c
index 860a160..c6eedec 100755 (executable)
--- a/backend.c
+++ b/backend.c
@@ -3720,15 +3720,6 @@ ParseBoard12(string)
     /* Update currentMove and known move number limits */
     newMove = newGame || moveNum > forwardMostMove;
 
-    /* [DM] If we found takebacks during icsEngineAnalyze try send to engine */
-    if (!newGame && appData.icsEngineAnalyze && moveNum < forwardMostMove) {
-        takeback = forwardMostMove - moveNum;
-        for (i = 0; i < takeback; i++) {
-             if (appData.debugMode) fprintf(debugFP, "take back move\n");
-             SendToProgram("undo\n", &first);
-        }
-    }
-
     if (newGame) {
        forwardMostMove = backwardMostMove = currentMove = moveNum;
        if (gameMode == IcsExamining && moveNum == 0) {
@@ -3741,6 +3732,20 @@ ParseBoard12(string)
        }
     } else if (moveNum == forwardMostMove + 1 || moveNum == forwardMostMove
               || (moveNum < forwardMostMove && moveNum >= backwardMostMove)) {
+#if ZIPPY
+       /* [DM] If we found takebacks during icsEngineAnalyze try send to engine */
+       /* [HGM] applied this also to an engine that is silently watching        */
+       if (appData.zippyPlay && moveNum < forwardMostMove && first.initDone &&
+           (gameMode == IcsObserving || gameMode == IcsExamining) &&
+           gameInfo.variant == currentlyInitializedVariant) {
+         takeback = forwardMostMove - moveNum;
+         for (i = 0; i < takeback; i++) {
+           if (appData.debugMode) fprintf(debugFP, "take back move\n");
+           SendToProgram("undo\n", &first);
+         }
+       }
+#endif
+
        forwardMostMove = moveNum;
        if (!pausing || currentMove > forwardMostMove)
          currentMove = forwardMostMove;
@@ -3751,12 +3756,20 @@ ParseBoard12(string)
            forwardMostMove = pauseExamForwardMostMove;
            return;
        }
-       forwardMostMove = backwardMostMove = currentMove = moveNum;
        if (gameMode == IcsExamining && moveNum > 0 && appData.getMoveList) {
+#if ZIPPY
+           if(appData.zippyPlay && forwardMostMove > 0 && first.initDone) {
+               // [HGM] when we will receive the move list we now request, it will be
+               // fed to the engine from the first move on. So if the engine is not
+               // in the initial position now, bring it there.
+               InitChessProgram(&first, 0);
+           }
+#endif
            ics_getting_history = H_REQUESTED;
            sprintf(str, "%smoves %d\n", ics_prefix, gamenum);
            SendToICS(str);
        }
+       forwardMostMove = backwardMostMove = currentMove = moveNum;
     }
     
     /* Update the clocks */