[dia] Bug 312641 - fix some remaining miscalculations with arcs

[Hans Breuer <hans src gnome org>]

commit 14a1d80d55ec529804c3cc5d8e0914c2cbaf7799
Author: Hans Breuer <hans breuer org>
Date:   Fri Jun 24 12:08:57 2011 +0200

    Bug 312641 - fix some remaining miscalculations with arcs
    
    Some conditions still/again produced vanishing of arcs.

 lib/diarenderer.c      |    2 +-
 objects/standard/arc.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/lib/diarenderer.c b/lib/diarenderer.c
index 55b1ec9..67b740f 100644
--- a/lib/diarenderer.c
+++ b/lib/diarenderer.c
@@ -1367,7 +1367,7 @@ draw_arc_with_arrows (DiaRenderer *renderer,
   }
 
   /* Only draw it if the original direction is preserved */
-  if ((angle2 > angle1) == clockwise)
+  if (is_right_hand (&new_startpoint, midpoint, &new_endpoint) == righthand)
     DIA_RENDERER_GET_CLASS(renderer)->draw_arc(renderer, &center, width, width,
 					       angle1, angle2, color);
 
diff --git a/objects/standard/arc.c b/objects/standard/arc.c
index 4e585f6..9900c07 100644
--- a/objects/standard/arc.c
+++ b/objects/standard/arc.c
@@ -758,7 +758,7 @@ arc_update_data(Arc *arc)
   y2 = endpoints[1].y;
   
   lensq = (x2-x1)*(x2-x1) + (y2-y1)*(y2-y1);
-  if (arc->curve_distance > 0.01)
+  if (fabs(arc->curve_distance) > 0.01)
     radius = lensq/(8*arc->curve_distance) + arc->curve_distance/2.0;
   else
     radius = 0.0; /* not really but used for bbox calculation below */