X-Git-Url: http://winboard.nl/cgi-bin?a=blobdiff_plain;f=book.c;h=a5aa6ab5084f597694994dfdbe598fcfaaf23b87;hb=c4545166b97f99043e21f352e1439af355da5d32;hp=e42b9c6e5099e0a3560bcd28b384e2d26dca88fc;hpb=07a96d271c45508c7b628f77a88b6a4032bb0fd8;p=xboard.git

diff --git a/book.c b/book.c
index e42b9c6..a5aa6ab 100644
--- a/book.c
+++ b/book.c
@@ -278,6 +278,23 @@ uint64 hash(int moveNr)
 {
     int r, f, p_enc, squareNr, pieceGroup;
     uint64 key=0, holdingsKey=0, Zobrist;
+    VariantClass v = gameInfo.variant;
+
+    switch(v) {
+	case VariantNormal:
+	case VariantFischeRandom: // compatible with normal
+	case VariantNoCastle:
+	case VariantXiangqi: // for historic reasons; does never collide anyway because of other King type
+	    break;
+	case VariantGiveaway: // in opening same as suicide
+	    key += VariantSuicide;
+	    break;
+	case VariantGothic: // these are special cases of CRC, and can share book
+	case VariantCapablanca:
+	    v = VariantCapaRandom;
+	default:
+	    key += v; // variant type incorporated in key to allow mixed books without collisions
+    }
 
     for(f=0; f<BOARD_WIDTH; f++){
         for(r=0; r<BOARD_HEIGHT;r++){
@@ -676,8 +693,10 @@ void SaveToBook(char *text)
     if(count != currentCount) {
 	do {
 	    for(i=0; i<len1; i++) buf2[i] = buf1[i]; len2 = len1;
-	    fseek(f, readpos, SEEK_SET);
-	    readpos += len1 = fread(buf1, 1, 4096, f);
+	    if(readpos > writepos) {
+		fseek(f, readpos, SEEK_SET);
+		readpos += len1 = fread(buf1, 1, 4096, f);
+	    } else len1 = 0; // wrote already past old EOF
 	    fseek(f, writepos, SEEK_SET);
 	    fwrite(buf2, 1, len2, f);
 	    writepos += len2;