Allow deletion of last book move

The book-edit function refused to delete the entiremove list,
for no good reason. This limitation now has been lifted.
Also the error message that the key for the current book entries
is different from that of the currentposition has been suppressed
if there were no entries found for the current position (so that the
book is positioned at the next key), so that it is possible to add
moves from scratch.

diff --git a/book.c b/book.c
index 4bc2521..3650b01 100644 (file)
--- a/book.c
+++ b/book.c
@@ -580,6 +580,7 @@ int TextToMoves(char *text, int moveNum, entry_t *entries)
        float dummy;
        int width = BOARD_RGHT - BOARD_LEFT;
 
+       entries[0].key = hashKey; // make sure key is returned even if no moves
        while((i=sscanf(text, "%f%%%d", &dummy, &w))==2 || (i=sscanf(text, "%d", &w))==1) {
            if(i == 2) text = strchr(text, '%') + 1;  // skip percentage
            if(w == 1) text = strstr(text, "1 ") + 2; // skip weight that could be recognized as move number one
@@ -651,11 +652,11 @@ void SaveToBook(char *text)
     int count = TextToMoves(text, currentMove, entries);
     int offset, i, len1=0, len2, readpos=0, writepos=0;
     FILE *f;
-    if(!count) return;
+    if(!count && !currentCount) return;
     f=fopen(appData.polyglotBook, "rb+");
     if(!f){    DisplayError("Polyglot book not valid", 0); return; }
     offset=find_key(f, entries[0].key, &entry);
-    if(entries[0].key != entry.key) {
+    if(entries[0].key != entry.key && currentCount) {
          DisplayError("Hash keys are different", 0);
          fclose(f);
          return;
@@ -680,3 +681,4 @@ void SaveToBook(char *text)
     }
     fclose(f);
 }
+