[recipes] Avoid a crash

[Matthias Clasen <matthiasc src gnome org>]

commit 0857b77cc8bd6b75661bc58792789c96d2f1b9b6
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Feb 18 10:20:24 2017 -0500

    Avoid a crash
    
    We shouldn't bring up the lightbox if we have no images to show.

 src/gr-image-page.c |    6 ++++--
 src/gr-window.c     |    2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)
---
diff --git a/src/gr-image-page.c b/src/gr-image-page.c
index 4fc3515..e6e56a4 100644
--- a/src/gr-image-page.c
+++ b/src/gr-image-page.c
@@ -332,6 +332,8 @@ void
 gr_image_page_show_image (GrImagePage *page,
                           int          idx)
 {
-        page->index = idx % page->images->len;
-        set_current_image (page);
+        if (page->images->len > 0) {
+                page->index = idx % page->images->len;
+                set_current_image (page);
+        }
 }
diff --git a/src/gr-window.c b/src/gr-window.c
index 05d3e94..9d5262a 100644
--- a/src/gr-window.c
+++ b/src/gr-window.c
@@ -965,7 +965,7 @@ gr_window_show_image (GrWindow *window,
                       GArray   *images,
                       int       index)
 {
-        if (images) {
+        if (images && images->len > 0) {
                 gr_image_page_set_images (GR_IMAGE_PAGE (window->image_page), images);
                 gr_image_page_show_image (GR_IMAGE_PAGE (window->image_page), index);
                 gtk_stack_set_visible_child_name (GTK_STACK (window->main_stack), "image");