[gthumb] fixed convertion to GdkPixbuf

[Paolo Bacchilega <paobac src gnome org>]

commit 8143f56c9791ad0c119dc40eaac85d3bce03b2fa
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Thu Feb 5 19:48:30 2015 +0100

    fixed convertion to GdkPixbuf

 gthumb/pixbuf-utils.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/gthumb/pixbuf-utils.c b/gthumb/pixbuf-utils.c
index ba1e971..51fe252 100644
--- a/gthumb/pixbuf-utils.c
+++ b/gthumb/pixbuf-utils.c
@@ -28,6 +28,7 @@
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include "cairo-utils.h"
 #include "pixbuf-utils.h"
+#include "gimp-op.h"
 
 
 GdkPixbuf *
@@ -70,14 +71,14 @@ _gdk_pixbuf_new_from_cairo_surface (cairo_surface_t *surface)
        while (height--) {
                guchar *s_iter = s_pixels;
                guchar *p_iter = p_pixels;
-               int     i;
+               int     i, temp;
 
                for (i = 0; i < width; i++) {
                        gdouble alpha_factor = (gdouble) 0xff / s_iter[CAIRO_ALPHA];
 
-                       p_iter[0] = (guchar) (alpha_factor * s_iter[CAIRO_RED]  + .5);
-                       p_iter[1] = (guchar) (alpha_factor * s_iter[CAIRO_GREEN] + .5);
-                       p_iter[2] = (guchar) (alpha_factor * s_iter[CAIRO_BLUE] + .5);
+                       p_iter[0] = CLAMP_PIXEL (alpha_factor * s_iter[CAIRO_RED]);
+                       p_iter[1] = CLAMP_PIXEL (alpha_factor * s_iter[CAIRO_GREEN]);
+                       p_iter[2] = CLAMP_PIXEL (alpha_factor * s_iter[CAIRO_BLUE]);
                        if (p_n_channels == 4)
                                p_iter[3] = s_iter[CAIRO_ALPHA];