Render a line for a path segment with a radius of zero

fixes #97

Author: bsweeney

src/Svg/Tag/Path.php

@@ -449,7 +449,12 @@ function drawArc(SurfaceInterface $surface, $fx, $fy, $coords)
         $toX = $tx - $fx;
         $toY = $ty - $fy;
 
-        if ($toX + $toY === 0) {
+        if ((float)($toX + $toY) === 0.0) {
+            return;
+        }
+
+        if ((float)abs($rx) == 0.0 || (float)abs($ry) === 0.0) {
+            $surface->lineTo($tx, $ty);
             return;
         }