[gtksourceview] StyleScheme: fix bug in secondary cursor color

[Sébastien Wilmet <swilmet src gnome org>]

commit e829ae10b18df3b2d439f38315328fef1846dc2a
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Mar 26 15:01:00 2016 +0100

    StyleScheme: fix bug in secondary cursor color
    
    Follow what is described in the Style Scheme Definition Reference.
    In fact it gives better results, but it's not perfect.

 gtksourceview/gtksourcestylescheme.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/gtksourceview/gtksourcestylescheme.c b/gtksourceview/gtksourcestylescheme.c
index c5297b2..b9da919 100644
--- a/gtksourceview/gtksourcestylescheme.c
+++ b/gtksourceview/gtksourcestylescheme.c
@@ -707,11 +707,11 @@ get_cursors_css_style (GtkSourceStyleScheme *scheme,
 
                gtk_style_context_restore (context);
 
-               /* shade the secondary cursor */
-               secondary_color.red = background_color->red * 0.5;
-               secondary_color.green = background_color->green * 0.5;
-               secondary_color.blue = background_color->blue * 0.5;
-               secondary_color.alpha = 1.0;
+               /* Blend primary cursor color with background color. */
+               secondary_color.red = (primary_color.red + background_color->red) * 0.5;
+               secondary_color.green = (primary_color.green + background_color->green) * 0.5;
+               secondary_color.blue = (primary_color.blue + background_color->blue) * 0.5;
+               secondary_color.alpha = (primary_color.alpha + background_color->alpha) * 0.5;
 
                gdk_rgba_free (background_color);
        }