[gnome-software] Never show a 'missing' icon when AppStream does not provide an app icon

[Richard Hughes <rhughes src gnome org>]

commit c955d3a16e10e0c633d26c73ee686591c35b634e
Author: Richard Hughes <richard hughsie com>
Date:   Thu Mar 28 11:33:24 2019 +0000

    Never show a 'missing' icon when AppStream does not provide an app icon
    
    Although this belies a metadata generation bug, fall back to showing the
    generic application icon rather than having a 'hole' in the UI where the icon
    would normally be.

 src/gs-app-row.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/src/gs-app-row.c b/src/gs-app-row.c
index 799b60aa..4b10be64 100644
--- a/src/gs-app-row.c
+++ b/src/gs-app-row.c
@@ -390,9 +390,14 @@ gs_app_row_refresh (GsAppRow *app_row)
        }
 
        /* pixbuf */
-       if (gs_app_get_pixbuf (priv->app) != NULL)
+       if (gs_app_get_pixbuf (priv->app) == NULL) {
+               gtk_image_set_from_icon_name (GTK_IMAGE (priv->image),
+                                             "application-x-executable",
+                                             GTK_ICON_SIZE_DIALOG);
+       } else {
                gs_image_set_from_pixbuf (GTK_IMAGE (priv->image),
                                          gs_app_get_pixbuf (priv->app));
+       }
 
        context = gtk_widget_get_style_context (priv->image);
        if (missing_search_result)