From 1fcb61cffe538c11a11fc2ec94d6470a61df019e Mon Sep 17 00:00:00 2001 From: Simon Tatham Date: Sun, 14 Mar 2021 22:05:23 +0000 Subject: [PATCH] Filling: fix assertion failure in 3x1 game generation. This would come up on the game id "3x1#12345", for example. The failing assertion was (s->board[f] != EMPTY) in expand(), called in turn from learn_expand_or_one(). It looks as if the problem was that the #define SENTINEL was set too small. It was intended to be a value that can't coincide with the true size of any region - and it was set to precisely the area of the whole board. But on a 3x1 grid, that _can_ coincide with the size of a region! So a board entry was set to a real region size, and then mistaken for SENTINEL by another part of the code. Easy fix: set SENTINEL to be sz+1. Now it really can't coincide with a region area. --- filling.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/filling.c b/filling.c index 3231384..a62161a 100644 --- a/filling.c +++ b/filling.c @@ -310,7 +310,7 @@ static void print_board(int *board, int w, int h) { static game_state *new_game(midend *, const game_params *, const char *); static void free_game(game_state *); -#define SENTINEL sz +#define SENTINEL (sz+1) static bool mark_region(int *board, int w, int h, int i, int n, int m) { int j;