[gtk] cssimagelinear: Make gradient offsets stay in [0, 1]

[Benjamin Otte <otte src gnome org>]

commit b21882bcea94fd9acf0edd9937e8318f134c7275
Author: Benjamin Otte <otte redhat com>
Date:   Fri Mar 29 05:01:33 2019 +0100

    cssimagelinear: Make gradient offsets stay in [0, 1]
    
    Fixes linear-gradient reftest

 gtk/gtkcssimagelinear.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkcssimagelinear.c b/gtk/gtkcssimagelinear.c
index 1253ed8bf9..5487767ae2 100644
--- a/gtk/gtkcssimagelinear.c
+++ b/gtk/gtkcssimagelinear.c
@@ -211,7 +211,10 @@ gtk_css_image_linear_snapshot (GtkCssImage        *image,
             continue;
         }
       else
-        pos = _gtk_css_number_value_get (stop->offset, length) / length;
+        {
+          pos = _gtk_css_number_value_get (stop->offset, length) / length;
+          pos = CLAMP (pos, 0.0, 1.0);
+        }
 
       pos = MAX (pos, offset);
       step = (pos - offset) / (i - last);