[gtk/fix-places-crash] gtkplacessidebar.c: add bookmark null checking

[Matthias Clasen <matthiasc src gnome org>]

commit c7f9c80eb52a3180b5de9961506367c998b95ba0
Author: Geyslan G. Bem <geyslan gmail com>
Date:   Tue Apr 27 11:42:55 2021 -0300

    gtkplacessidebar.c: add bookmark null checking
    
    This fixes nautilus crash and perhaps other callers issues.
    Nautilus (and sometimes glib) crashes with malformed URI inside of the
    bookmarks file .config/gtk-3.0/bookmarks when it has no LABEL.
    
    This is result from the closed glib MR #2065 analysis and agreement.
    https://gitlab.gnome.org/GNOME/glib/-/merge_requests/2065#note_1091979
    
    Signed-off-by: Geyslan G. Bem <geyslan gmail com>
    
    Fixes: #4643

 gtk/gtkplacessidebar.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/gtk/gtkplacessidebar.c b/gtk/gtkplacessidebar.c
index 118739fdd2..7ce19e8851 100644
--- a/gtk/gtkplacessidebar.c
+++ b/gtk/gtkplacessidebar.c
@@ -866,6 +866,9 @@ on_bookmark_query_info_complete (GObject      *source,
     {
       /* Don't add non-UTF-8 bookmarks */
       bookmark_name = g_file_get_basename (root);
+      if (bookmark_name == NULL)
+        goto out;
+
       if (!g_utf8_validate (bookmark_name, -1, NULL))
         {
           g_free (bookmark_name);