Fix alpha bug, promotion bug, highlighting and move printing bugs

Two crippling bugs fixed: alpha was not  reset at the start of later
iterations, and promotions were added to the move-list of deeper nodes
due to spoiling of the global nonCapts.
Essential deferrals were not correctly flagged on input moves.
Printing move lists could miss some initial moves, wrecking highlighting.

diff --git a/hachu.c b/hachu.c
index 14db902..1ea7853 100644 (file)
--- a/hachu.c
+++ b/hachu.c
@@ -1184,7 +1184,7 @@ Search (int alpha, int beta, int difEval, int depth, int oldPromo, int promoSupp
 {\r
   int i, j, k, firstMove, oldMSP = msp, curMove, sorted, bad, phase, king, iterDep, replyDep, nextVictim, to, defer, dubious, bestMoveNr;\r
   int savHashL = hashKeyL, savHashH = hashKeyH;\r
-  int score, bestScore, curEval;\r
+  int score, bestScore, curEval, iterAlpha;\r
   Move move, nullMove;\r
   UndoInfo tb;\r
 if(PATH) printf("search(%d) %d-%d eval=%d, stm=%d\n",depth,alpha,beta,difEval,stm),fflush(stdout);\r
@@ -1206,11 +1206,11 @@ if(PATH) printf("search(%d) %d-%d eval=%d, stm=%d\n",depth,alpha,beta,difEval,st
   alpha -= (alpha < curEval);\r
   beta  -= (beta <= curEval);\r
 \r
-  firstMove = curMove = sorted = nonCapts = msp += 20; // leave 20 empty slots in front of move list\r
+  firstMove = curMove = sorted = msp += 20; // leave 20 empty slots in front of move list\r
   phase = 0; iterDep=1; replyDep = (depth < 1 ? depth : 1) - 1;\r
   do {\r
 if(flag && depth>= 0) printf("iter %d:%d\n", depth,iterDep),fflush(stdout);\r
-    bestScore = -INF; bestMoveNr = 0;\r
+    iterAlpha = alpha; bestScore = -INF; bestMoveNr = 0;\r
     for(curMove = firstMove; ; curMove++) { // loop over moves\r
 if(flag && depth>= 0) printf("phase=%d: first/curr/last = %d / %d / %d\n", phase, firstMove, curMove, msp);fflush(stdout);\r
       // MOVE SOURCE\r
@@ -1224,7 +1224,7 @@ if(flag && depth>= 0) printf("phase=%d: first/curr/last = %d / %d / %d\n", phase
 #if 0\r
            if(curEval >= beta) {\r
              stm ^= WHITE;\r
-             score = -Search(-beta, -alpha, difEval, depth-3, promoSuppress & SQUARE, ABSENT);\r
+             score = -Search(-beta, -iterAlpha, difEval, depth-3, promoSuppress & SQUARE, ABSENT);\r
              stm ^= WHITE;\r
              if(score >= beta) { msp = oldMSP; return score + (score < curEval); }\r
            }\r
@@ -1263,6 +1263,7 @@ if(flag && depth>= 0) printf("phase=%d: first/curr/last = %d / %d / %d\n", phase
            if(depth <= 0) goto cutoff;\r
            phase = 6;\r
          case 6: // non-captures\r
+           nonCapts = msp;\r
            nullMove = GenNonCapts(oldPromo);\r
            phase = 7;\r
            sorted = msp; // do not sort noncapts\r
@@ -1307,7 +1308,7 @@ if(PATH) pmap(attacks, stm);
         if(score == -INF) { moveStack[curMove] = 0; goto abortMove; }\r
       }\r
 #if 1\r
-      score = -Search(-beta, -alpha, -difEval - tb.booty, replyDep, promoSuppress & ~PROMOTE, defer);\r
+      score = -Search(-beta, -iterAlpha, -difEval - tb.booty, replyDep, promoSuppress & ~PROMOTE, defer);\r
 #else\r
       score = 0;\r
 #endif\r
@@ -1325,8 +1326,8 @@ if(PATH) printf("%d:%2d:%d %3d %6x %-10s %6d %6d\n", level, depth, iterDep, curM
       // ALPHA-BETA STUFF\r
       if(score > bestScore) {\r
        bestScore = score; bestMoveNr = curMove;\r
-       if(score > alpha) {\r
-         alpha = score;\r
+       if(score > iterAlpha) {\r
+         iterAlpha = score;\r
          if(curMove < firstMove + 5) { // if not too much work, sort move to front\r
            int i;\r
            for(i=curMove; i>firstMove; i--) {\r
@@ -1554,11 +1555,11 @@ MapFromScratch(attacks);
       if(!(flags & promoBoard[t] & (CANT_DEFER | LAST_RANK))) { // but change it into a deferral if that is allowed\r
        moveStack[i] &= ~PROMOTE;\r
        if(p[board[f]].value == 40) p[board[f]].promoFlag &= LAST_RANK; else\r
-       if(!(flags & promoBoard[t])) moveStack[i] |= DEFER; // came from outside zone, so essential deferral\r
+       if(!(flags & promoBoard[f])) moveStack[i] |= DEFER; // came from outside zone, so essential deferral\r
       }\r
     }\r
     if(i >= retMSP)\r
-      for(i=20; i<retMSP; i++) printf("# %d. %08x %08x %s\n", i-20, moveStack[i], ret, MoveToText(moveStack[i], 0));\r
+      for(i=retFirst; i<retMSP; i++) printf("# %d. %08x %08x %s\n", i-20, moveStack[i], ret, MoveToText(moveStack[i], 0));\r
   }\r
   return (i >= retMSP ? INVALID : moveStack[i]);\r
 }\r
@@ -1584,7 +1585,7 @@ flag=0;
   if(!cnt) { // no moves from given square\r
     if(sqr != lastPut) return; // refrain from sending empty FEN\r
     // we lifted a piece for second leg of move\r
-    for(i=20; i<retMSP; i++) {\r
+    for(i=retFirst; i<retMSP; i++) {\r
       if(lastLift == (moveStack[i]>>SQLEN & SQUARE)) {\r
        int e, t = moveStack[i] & SQUARE;\r
        if(t < SPECIAL) continue; // only special moves\r