--- ray/src/px/pcond4.c	1997/01/11 19:34:22	3.13
+++ ray/src/px/pcond4.c	1997/08/13 11:24:48	3.15
@@ -108,7 +108,8 @@ compveil()				/* compute veiling image */
 					t2sum += t2;
 				}
 			/* VADAPT of original is subtracted in addveil() */
-			scalecolor(vsum, VADAPT/t2sum);
+			if (t2sum > FTINY)
+				scalecolor(vsum, VADAPT/t2sum);
 			copycolor(veilscan(py)[px], vsum);
 		}
 					/* modify FOV sample image */
@@ -285,11 +286,8 @@ SCANBAR	*sb;
 					/* get scanlines */
 	sl0 = getascan(sb, iy);
 #ifdef DEBUG
-	if (sl0 == NULL) {
-		fprintf(stderr, "%s: internal - cannot backspace in ascanval\n",
-				progname);
-		abort();
-	}
+	if (sl0 == NULL)
+		error(INTERNAL, "cannot backspace in ascanval");
 #endif
 	sl1 = getascan(sb, iy+1);
 					/* 2D linear interpolation */