r6160, I completely failed to ensure that generated grids were _at
most_ the required difficulty. It appears to have been only random
chance that prevented a request for a Trivial puzzle from producing
Extreme. Here's a one-line fix.
[originally from svn r6298]
[r6160 ==
e55838bc9b0d173ca539d0cfe714495b5c12b9dd]
grid2[coords[2*j+1]*cr+coords[2*j]] = 0;
ret = solver(c, r, grid2, maxdiff);
- if (ret != DIFF_IMPOSSIBLE && ret != DIFF_AMBIGUOUS) {
+ if (ret <= maxdiff) {
for (j = 0; j < ncoords; j++)
grid[coords[2*j+1]*cr+coords[2*j]] = 0;
}