* libee/sprite.c:

+ Added sanity checks in ee_sprite_* functions.
  * libee/conic.c:
    + Use ellipsepoints() in ee_draw_circle().

libee/conic.c

@@ -26,6 +26,8 @@
 
 #include "ee.h"
 
+static void ellipsepoints(int, int, int, int, char);
+
 void ee_draw_circle(int x, int y, int r, char c)
 {
     int test, dx, dy;
@@ -33,28 +35,13 @@ void ee_draw_circle(int x, int y, int r, char c)
     /* Optimized Bresenham. Kick ass. */
     for(test = 0, dx = 0, dy = r ; dx <= dy ; dx++)
     {
-        ee_putcharTO(x + dx, y + dy / 2, c);
-        ee_putcharTO(x - dx, y + dy / 2, c);
-        ee_putcharTO(x + dx, y - dy / 2, c);
-        ee_putcharTO(x - dx, y - dy / 2, c);
-
-        ee_putcharTO(x + dy, y + dx / 2, c);
-        ee_putcharTO(x - dy, y + dx / 2, c);
-        ee_putcharTO(x + dy, y - dx / 2, c);
-        ee_putcharTO(x - dy, y - dx / 2, c);
+        ellipsepoints(x, y, dx, dy, c);
+        ellipsepoints(x, y, dy, dx, c);
 
         test += test > 0 ? dx - dy-- : dx;
     }
 }
 
-static void ellipsepoints(int xo, int yo, int x, int y, char c)
-{
-    ee_putcharTO(xo + x, yo + y, c);
-    ee_putcharTO(xo - x, yo + y, c);
-    ee_putcharTO(xo + x, yo - y, c);
-    ee_putcharTO(xo - x, yo - y, c);
-}
-
 void ee_draw_ellipse(int xo, int yo, int a, int b, char c)
 {
     int d2;
@@ -97,3 +84,11 @@ void ee_draw_ellipse(int xo, int yo, int a, int b, char c)
     }
 }
 
+static void ellipsepoints(int xo, int yo, int x, int y, char c)
+{
+    ee_putcharTO(xo + x, yo + y, c);
+    ee_putcharTO(xo - x, yo + y, c);
+    ee_putcharTO(xo + x, yo - y, c);
+    ee_putcharTO(xo - x, yo - y, c);
+}
+

libee/sprite.c

@@ -130,6 +130,9 @@ struct ee_sprite *ee_load_sprite(const char *file)
 
 void ee_set_sprite_frame(struct ee_sprite *sprite, int f)
 {
+    if(sprite == NULL)
+        return;
+
     if(f < 0 || f >= sprite->nf)
         return;
 
@@ -138,13 +141,21 @@ void ee_set_sprite_frame(struct ee_sprite *sprite, int f)
 
 int ee_get_sprite_frame(struct ee_sprite *sprite)
 {
+    if(sprite == NULL)
+        return -1;
+
     return sprite->f;
 }
 
 void ee_draw_sprite(int x, int y, struct ee_sprite *sprite)
 {
     int i, j;
-    struct ee_frame *frame = &sprite->frames[sprite->f];
+    struct ee_frame *frame;
+
+    if(sprite == NULL)
+        return;
+
+    frame = &sprite->frames[sprite->f];
 
     for(j = 0; j < frame->h; j++)
     {
@@ -165,6 +176,9 @@ void ee_free_sprite(struct ee_sprite *sprite)
 {
     int i;
 
+    if(sprite == NULL)
+        return;
+
     for(i = sprite->nf; i--;)
     {
         struct ee_frame *frame = &sprite->frames[i];