shithub: puzzles

Don't allow moves that change the constraints in Unequal Unequal has a flags word per cell. Some of those flags are fixed, like the locations of the ">" signs, but others indicate errors and are used to allow the player to mark clues as "spent". Move strings beginning with "F" allow the user to change the "spent" flags, but they shouldn't allow the user to change any other flags, especially those marking the constraints. Without this fix, the following save file gives a "solver_nminmax: Assertion `x >= 0 && y >= 0 && x < o && y < o' failed" after it adds a clue that points off the board: SAVEFILE:41:Simon Tatham's Portable Puzzle Collection GAME :7:Unequal PARAMS :3:3e0 CPARAMS :3:3e0 DESC :17:0,0,0,0,0,0,0,0,0 NSTATES :2:3 STATEPOS:1:3 MOVE :6:F2,0,4 MOVE :1:H

--- a/unequal.c

+++ b/unequal.c

@@ -84,6 +84,7 @@

 #define ADJ_TO_SPENT(x) ((x) << 9)

 #define F_ERROR_MASK (F_ERROR|F_ERROR_UP|F_ERROR_RIGHT|F_ERROR_DOWN|F_ERROR_LEFT)

+#define F_SPENT_MASK (F_SPENT_UP|F_SPENT_RIGHT|F_SPENT_DOWN|F_SPENT_LEFT)

 struct game_state {

     int order;

@@ -1706,7 +1707,8 @@

         check_complete(ret->nums, ret, true);

         return ret;

     } else if (move[0] == 'F' && sscanf(move+1, "%d,%d,%d", &x, &y, &n) == 3 &&

-	       x >= 0 && x < state->order && y >= 0 && y < state->order) {

+	       x >= 0 && x < state->order && y >= 0 && y < state->order &&

+               (n & ~F_SPENT_MASK) == 0) {

 	ret = dup_game(state);

 	GRID(ret, flags, x, y) ^= n;

 	return ret;