Chris Boyle reports that if you right-drag a numbered cell off the
grid, _all_ numbered cells (except the immutable initial clues) get
reset to blank, because this is treated as an attempt to erase a whole
chain of linked cells (of the form a,a+1,...,a_k) and the cells with
definite numbers are all treated as 'chain 0'.
In that situation, I now substitute the same behaviour you'd get by
left-dragging the numbered cell off the board, i.e. erase _just_ that
cell and not the whole of the rest of the puzzle.
(The previous unintended behaviour was a UI action you surely never
want - and Chris also reports that due to the Android front end's way
of representing right-drags, it's especially easy to hit by mistake.)
si = sy*w+sx; ei = ey*w+ex;
makelink(ret, si, ei);
} else if (sscanf(move, "%c%d,%d", &c, &sx, &sy) == 3) {
+ int sset;
+
if (c != 'C' && c != 'X') return NULL;
if (!INGRID(state, sx, sy)) return NULL;
si = sy*w+sx;
ret = dup_game(state);
- if (c == 'C') {
+ sset = state->nums[si] / (state->n+1);
+ if (c == 'C' || (c == 'X' && sset == 0)) {
/* Unlink the single cell we dragged from the board. */
unlink_cell(ret, si);
} else {
- int i, set, sset = state->nums[si] / (state->n+1);
+ int i, set;
for (i = 0; i < state->n; i++) {
/* Unlink all cells in the same set as the one we dragged
* from the board. */