From 460f8c277b3b40b2fadbb9523fa1dfc502555979 Mon Sep 17 00:00:00 2001
From: David Turner
Date: Thu, 13 Jan 2011 20:06:23 +0000
Subject: PARALLACTION: Fixed Limit Values in Big Red Adventure Walker Code.

This corrects the Valgrind invalid reads associated with the IS_PATH_CLEAR() check reading beyond the data buffer and probably improves the pathfinding behaviour.
Thanks to fuzzie for suggesting this patch.

svn-id: r55231
---
 engines/parallaction/walk.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'engines/parallaction')

diff --git a/engines/parallaction/walk.cpp b/engines/parallaction/walk.cpp
index 3fa71d7a27..7efc1a1e4c 100644
--- a/engines/parallaction/walk.cpp
+++ b/engines/parallaction/walk.cpp
@@ -656,7 +656,7 @@ void PathWalker_BR::doWalk(State &s) {
 
 	Common::Point p(*s._walkPath.begin());
 
-	if (s._startFoot.y < p.y && s._startFoot.y < maxY && IS_PATH_CLEAR(s._startFoot.x, yStep + s._startFoot.y)) {
+	if (s._startFoot.y < p.y && (s._startFoot.y + yStep) < maxY && IS_PATH_CLEAR(s._startFoot.x, s._startFoot.y + yStep)) {
 		if (yStep + s._startFoot.y <= p.y) {
 			s._fieldC = 1;
 			delta.y = yStep;
@@ -667,7 +667,7 @@ void PathWalker_BR::doWalk(State &s) {
 		}
 		s._dirFrame = 9;
 	} else
-	if (s._startFoot.y > p.y && s._startFoot.y > minY && IS_PATH_CLEAR(s._startFoot.x, s._startFoot.y - yStep)) {
+	if (s._startFoot.y > p.y && (s._startFoot.y - yStep) > minY && IS_PATH_CLEAR(s._startFoot.x, s._startFoot.y - yStep)) {
 		if (s._startFoot.y - yStep >= p.y) {
 			s._fieldC = 1;
 			delta.y = yStep;
@@ -679,7 +679,7 @@ void PathWalker_BR::doWalk(State &s) {
 		s._dirFrame = 0;
 	}
 
-	if (s._startFoot.x < p.x && s._startFoot.x < maxX && IS_PATH_CLEAR(s._startFoot.x + xStep, s._startFoot.y)) {
+	if (s._startFoot.x < p.x && (s._startFoot.x + xStep) < maxX && IS_PATH_CLEAR(s._startFoot.x + xStep, s._startFoot.y)) {
 		if (s._startFoot.x + xStep <= p.x) {
 			s._fieldC = 1;
 			delta.x = xStep;
@@ -692,7 +692,7 @@ void PathWalker_BR::doWalk(State &s) {
 			s._dirFrame = 18;	// right
 		}
 	} else
-	if (s._startFoot.x > p.x && s._startFoot.x > minX && IS_PATH_CLEAR(s._startFoot.x - xStep, s._startFoot.y)) {
+	if (s._startFoot.x > p.x && (s._startFoot.x - xStep) > minX && IS_PATH_CLEAR(s._startFoot.x - xStep, s._startFoot.y)) {
 		if (s._startFoot.x - xStep >= p.x) {
 			s._fieldC = 1;
 			delta.x = xStep;
-- 
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