[gdk-pixbuf] gif: Fix area-updated height

[Bastien Nocera <hadess src gnome org>]

commit a6b07899b11b10647168c5e35a9d6c809c38a5d5
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Dec 29 17:09:30 2016 +0100

    gif: Fix area-updated height
    
    The upper and lower bounds when an area is updated are inclusive
    coordinates, so the height would be upper - lower + 1, not
    upper - lower, which would exclude the upper line.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=581484

 gdk-pixbuf/io-gif.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gdk-pixbuf/io-gif.c b/gdk-pixbuf/io-gif.c
index 5b30093..8991397 100644
--- a/gdk-pixbuf/io-gif.c
+++ b/gdk-pixbuf/io-gif.c
@@ -1068,11 +1068,11 @@ gif_get_lzw (GifContext *context)
         
        if (bound_flag && context->update_func) {
                if (lower_bound <= upper_bound && first_pass == context->draw_pass) {
-                        maybe_update (context, 
+                        maybe_update (context,
                                       context->frame->x_offset,
                                       context->frame->y_offset + lower_bound,
                                       gdk_pixbuf_get_width (context->frame->pixbuf),
-                                      upper_bound - lower_bound);
+                                      upper_bound - lower_bound + 1);
                } else {
                        if (lower_bound <= upper_bound) {
                                 maybe_update (context,