[gnome-autoar/wip/oholy/extractor-raw-format-fix: 3/4] extractor: Fix extraction to root directory

[Ondrej Holy <oholy src gnome org>]

commit 7237276439281abfedd619ecf6f5c17fae411137
Author: Ondrej Holy <oholy redhat com>
Date:   Tue Nov 30 13:45:07 2021 +0100

    extractor: Fix extraction to root directory
    
    An extraction to the root of an archive which contains the "/" path
    leads to crashes. Let's handle this rare corner case.
    
    Relates: https://gitlab.gnome.org/GNOME/gnome-autoar/-/issues/38

 gnome-autoar/autoar-extractor.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)
---
diff --git a/gnome-autoar/autoar-extractor.c b/gnome-autoar/autoar-extractor.c
index bb60901..ab68c47 100644
--- a/gnome-autoar/autoar-extractor.c
+++ b/gnome-autoar/autoar-extractor.c
@@ -857,6 +857,14 @@ autoar_extractor_get_common_prefix (GList *files,
   while (!g_file_has_parent (prefix, root)) {
     file = g_file_get_parent (prefix);
     g_object_unref (prefix);
+
+    /* This can happen if the archive contains the "/" path and the destination
+     * is "/" as well.
+     */
+    if (file == NULL) {
+      return NULL;
+    }
+
     prefix = file;
   }
 
@@ -984,7 +992,7 @@ autoar_extractor_do_write_entry (AutoarExtractor      *self,
   {
     GFile *parent;
     parent = g_file_get_parent (dest);
-    if (!g_file_query_exists (parent, self->cancellable))
+    if (parent && !g_file_query_exists (parent, self->cancellable))
       g_file_make_directory_with_parents (parent,
                                           self->cancellable,
                                           NULL);