shithub: puzzles

Download patch

ref: 96315bc2baecb68040600cf93da4b4ce729e1acc
parent: 4a202808ee0be91d3a346076e71f45403bfa41de
author: Simon Tatham <[email protected]>
date: Mon Jan 12 15:30:12 EST 2009 

Patch from James H to fix some off-by-one errors in Guess's click
rectangle checking, preventing array bounds violation.

[originally from svn r8409]


--- a/guess.c
+++ b/guess.c
@@ -655,20 +655,24 @@
 
     if (from->solved) return NULL;
 
-    if (x >= COL_OX && x <= (COL_OX + COL_W) &&
-        y >= COL_OY && y <= (COL_OY + COL_H)) {
+    if (x >= COL_OX && x < (COL_OX + COL_W) &&
+        y >= COL_OY && y < (COL_OY + COL_H)) {
         over_col = ((y - COL_OY) / PEGOFF) + 1;
+        assert(over_col >= 1 && over_col <= ds->colours->npegs);
     } else if (x >= guess_ox &&
-               y >= guess_oy && y <= (guess_oy + GUESS_H)) {
-        if (x <= (guess_ox + GUESS_W)) {
+               y >= guess_oy && y < (guess_oy + GUESS_H)) {
+        if (x < (guess_ox + GUESS_W)) {
             over_guess = (x - guess_ox) / PEGOFF;
+            assert(over_guess >= 0 && over_guess < ds->solution->npegs);
         } else {
             over_hint = 1;
         }
-    } else if (x >= guess_ox && x <= (guess_ox + GUESS_W) &&
+    } else if (x >= guess_ox && x < (guess_ox + GUESS_W) &&
                y >= GUESS_OY && y < guess_oy) {
         over_past_guess_y = (y - GUESS_OY) / PEGOFF;
         over_past_guess_x = (x - guess_ox) / PEGOFF;
+        assert(over_past_guess_y >= 0 && over_past_guess_y < from->next_go);
+        assert(over_past_guess_x >= 0 && over_past_guess_x < ds->solution->npegs);
     }
     debug(("make_move: over_col %d, over_guess %d, over_hint %d,"
            " over_past_guess (%d,%d)", over_col, over_guess, over_hint,