[gthumb] check if variable is null before using it

[Paolo Bacchilega <paobac src gnome org>]

commit 8e6105781471f0a1b7ceb0b842370b57d296ffec
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Wed Oct 25 19:04:04 2017 +0200

    check if variable is null before using it

 gthumb/gth-browser.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gthumb/gth-browser.c b/gthumb/gth-browser.c
index 7fd8ede..9b34fa8 100644
--- a/gthumb/gth-browser.c
+++ b/gthumb/gth-browser.c
@@ -1295,6 +1295,11 @@ requested_folder_attributes_ready_cb (GObject  *file_source,
                return;
        }
 
+       if (browser->priv->location == NULL) {
+               load_data_free (load_data);
+               return;
+       }
+
        gth_file_data_set_info (browser->priv->location, load_data->requested_folder->info);
 
        browser->priv->current_sort_type = gth_main_get_sort_type (g_file_info_get_attribute_string 
(browser->priv->location->info, "sort::type"));