Merge pull request #336 from toxieainc/master

Add some potential out-of-bounds access prevention and wrong pixel wrapping

Author: DCurrent

engine/openbor.c

@@ -44341,7 +44341,7 @@ void spawnplayer(int index)
     //////////////////checking holes/ walls///////////////////////////////////
     for(xc = 0; xc < videomodes.hRes / 4; xc++)
     {
-        if(p.position.x > videomodes.hRes)
+        if(p.position.x >= videomodes.hRes)
         {
             p.position.x -= videomodes.hRes;
         }

engine/openborscript.c

@@ -16156,7 +16156,7 @@ HRESULT openbor_getgfxproperty(ScriptVariant **varlist , ScriptVariant **pretvar
         {
         case bitmap_magic: //As long as the two structures are identical...
         case screen_magic:
-            if(x < 0 || x >= screen->width || y < 0 || y >= screen->height)
+            if((unsigned)x >= (unsigned)screen->width || (unsigned)y >= (unsigned)screen->height) // includes checks for <0
             {
                 v = 0;
             }
@@ -16180,7 +16180,7 @@ HRESULT openbor_getgfxproperty(ScriptVariant **varlist , ScriptVariant **pretvar
             }
             break;
         case sprite_magic:
-            if(x < 0 || x >= sprite->width || y < 0 || y >= sprite->height)
+            if((unsigned)x >= (unsigned)sprite->width || (unsigned)y >= (unsigned)sprite->height) // includes checks for <0
             {
                 v = 0;
             }

engine/source/gamelib/draw.c

@@ -270,7 +270,7 @@ void _putpixel(int x, int y, int colour, s_screen *screen, int alpha)
 {
     int pixind;
     unsigned char *lut;
-    if((unsigned)x > screen->width || (unsigned)y > screen->height)
+    if((unsigned)x >= (unsigned)screen->width || (unsigned)y >= (unsigned)screen->height)
     {
         return;
     }

engine/source/gamelib/draw16.c

@@ -274,7 +274,7 @@ void _putpixel16(unsigned x, unsigned y, unsigned short colour, s_screen *screen
     int pixind;
     unsigned short *data ;
     unsigned short(*blendfp)(unsigned short, unsigned short);
-    if(x > screen->width || y > screen->height)
+    if(x >= (unsigned)screen->width || y >= (unsigned)screen->height)
     {
         return;
     }
@@ -283,5 +283,3 @@ void _putpixel16(unsigned x, unsigned y, unsigned short colour, s_screen *screen
     blendfp = getblendfunction16(alpha);
     __putpixel16(data);
 }
-
-

engine/source/gamelib/draw32.c

@@ -277,7 +277,7 @@ void _putpixel32(unsigned x, unsigned y, unsigned colour, s_screen *screen, int
     int pixind;
     unsigned *data ;
     unsigned(*blendfp)(unsigned, unsigned);
-    if(x > screen->width || y > screen->height)
+    if(x >= (unsigned)screen->width || y >= (unsigned)screen->height)
     {
         return;
     }
@@ -287,5 +287,3 @@ void _putpixel32(unsigned x, unsigned y, unsigned colour, s_screen *screen, int
     blendfp = getblendfunction32(alpha);
     __putpixel32(data);
 }
-
-