[gimp] app: fix the angular value when tilt_y == tilt_x == 0.0.

[Jehan Pagès <jehanp src gnome org>]

commit 123a9092edd20a2c22ab531c63da7e2fa376c663
Author: Jehan <jehan girinstud io>
Date:   Mon Nov 7 13:39:09 2016 +0100

    app: fix the angular value when tilt_y == tilt_x == 0.0.
    
    Further improves commit bb17853. We can see in the generic tilt
    computation that if tilt_y is 0, whatever the value of tilt_x, tilt
    becomes 0.

 app/core/gimpdynamicsoutput.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/app/core/gimpdynamicsoutput.c b/app/core/gimpdynamicsoutput.c
index 9bb1eb3..51b9b7f 100644
--- a/app/core/gimpdynamicsoutput.c
+++ b/app/core/gimpdynamicsoutput.c
@@ -569,12 +569,12 @@ gimp_dynamics_output_get_angular_value (GimpDynamicsOutput *output,
 
       if (tilt_x == 0.0)
         {
-          if (tilt_y >= 0.0)
+          if (tilt_y > 0.0)
             tilt = 0.25;
           else if (tilt_y < 0.0)
             tilt = 0.75;
           else
-            tilt = -1.0;
+            tilt = 0.0;
         }
       else
         {