shithub: puzzles

Tolerate incorrect solutions in Inertia The "solve" operation in Inertia generates a proposed solution as a move string. But if such a move string is loaded from a save file it might not actually describe a solution. If that happens then it's possible to reach the end of the "solution" without winning, and doing so should probably cause a recalculation of the solution rather than an assertion failure ("execute_move: Assertion `ret->solnpos < ret->soln->len' failed."). I am a little concerned by the way that normal solve operations end up encoded in the save file, but the re-solvings caused by going off course don't, but I haven't got a good answer to that. Here's a save file that demonstrates the assertion failure: SAVEFILE:41:Simon Tatham's Portable Puzzle Collection GAME :7:Inertia PARAMS :3:8x8 CPARAMS :3:8x8 DESC :64:sbgwsmswwgggwggmmbwgwbssbwbsbwbbwsSmwbbsbbmggbmssgmgwbmmwmbmmwsw NSTATES :2:3 STATEPOS:1:1 MOVE 000:2:S0 MOVE 000:2:00

--- a/inertia.c

+++ b/inertia.c

@@ -1741,11 +1741,10 @@

     if (ret->soln) {

 	if (ret->dead || ret->gems == 0)

 	    discard_solution(ret);

-	else if (ret->soln->list[ret->solnpos] == dir) {

+	else if (ret->soln->list[ret->solnpos] == dir &&

+            ret->solnpos+1 < ret->soln->len)

 	    ++ret->solnpos;

-	    assert(ret->solnpos < ret->soln->len); /* or gems == 0 */

-	    assert(!ret->dead); /* or not a solution */

-	} else {

+	else {

 	    const char *error = NULL;

             char *soln = solve_game(NULL, ret, NULL, &error);

 	    if (!error) {

--

⑨