1 files changed, 10 insertions, 0 deletions
diff --git a/src/eval.c b/src/eval.c
index eb6e118..63fd301 100755
--- a/src/eval.c
+++ b/src/eval.c
@@ -1149,6 +1149,16 @@ Return value:
     PIECE p;
     CHAR ch;
 
+    // g_SwapTable is only [14][32][32] (data.c) -- this is the bound
+    // that actually matters, not just "no garbage above bit 7" below.
+    // PAWN_BIT..KING_BIT briefly didn't fit in bits 0-4 earlier this
+    // session (when _WhoControlsSquareFast was converted to read them
+    // directly instead of going through the old ATTACK_BITV struct)
+    // and silently indexed out of bounds on every attacked square --
+    // the (& 0xFFFFFF00) checks below never caught it (board_
+    // representation/EVAL.md section 9).
+    ASSERT(uWhite < 32);
+    ASSERT(uBlack < 32);
     ASSERT((uWhite & 0xFFFFFF00) == 0);
     ASSERT((uBlack & 0xFFFFFF00) == 0);