Mercurial > hg > terminal-chess / file diff

--- a/src/chess/rules.c	Thu Jul 23 11:37:35 2026 +0200
+++ b/src/chess/rules.c	Fri Jul 24 12:42:57 2026 +0200
@@ -337,8 +337,9 @@
 
 static int validate_move_rules(GameState *gamestate, Move *move) {
     /* validate indices (don't trust opponent) */
-    if (!chkidx(move)) {
-        return INVALID_POSITION;
+    if (!isidx(move->fromrow) || !isidx(move->fromfile) ||
+        !isidx(move->torow) || !isidx(move->tofile)) {
+        return INVALID_MOVE_SYNTAX;
     }
     
     /* must move */
@@ -844,8 +845,13 @@
 
     move->piece |= color;
 
-    if (!chkidx_to(move)) {
-        return INVALID_POSITION;
+    /* up to this point
+     * destination indices must be specified and valid
+     * source indices must either be valid or unspecified
+     */
+    if (!isidxr(move->fromrow) || !isidxr(move->fromfile) ||
+        !isidx(move->torow) || !isidx(move->tofile)) {
+        return INVALID_MOVE_SYNTAX;
     }
 
     return VALID_MOVE_SYNTAX;
@@ -858,8 +864,6 @@
         if (move->fromfile == POS_UNSPECIFIED
             || move->fromrow == POS_UNSPECIFIED) {
             return getlocation(gamestate, move);
-        } else if (!chkidx_from(move)) {
-            return INVALID_POSITION;
         }
     }
     return result;