bitbake: toaster: Add fake entry to Target_File for filesystem root

The files-in-image.txt file is produced by bitbake after an
image is created, listing all the files in the image.
However, this list doesn't include the root directory ('/').

buildinfohelper.py then tries to construct the filesystem
tree from this file, assuming that every directory apart from
the root directory (which is special-cased) can be assigned
a parent. But because the root directory isn't listed in
files-in-image.txt, an object for the root directory is never
created.

The direct subdirectories of the root ('./bin', './usr' etc.)
then can't be assigned a parent directory, as the object
representing the root directory doesn't exist. This
results in a Target_File lookup error and causes the
directory listing page to fail.

Fix this by creating a fake entry for the root directory
in the Target_File table, so that the direct subdirectories
of / can be assigned a parent. Note that it doesn't matter
that the root is faked, as its properties are never shown
in the directory structure tree.

[YOCTO #8280]

(Bitbake rev: a4015768183e5a3fa39a6c2b4dea0088ca182d80)

Signed-off-by: Elliot Smith <elliot.smith@intel.com>
Signed-off-by: brian avery <avery.brian@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/ui/buildinfohelper.py

@@ -338,26 +338,29 @@ class ORMWrapper(object):
         files = filedata['files']
         syms = filedata['syms']
 
-        # we insert directories, ordered by name depth
+        # always create the root directory as a special case;
+        # note that this is never displayed, so the owner, group,
+        # size, permission are irrelevant
+        tf_obj = Target_File.objects.create(target = target_obj,
+                                            path = '/',
+                                            size = 0,
+                                            owner = '',
+                                            group = '',
+                                            permission = '',
+                                            inodetype = Target_File.ITYPE_DIRECTORY)
+        tf_obj.save()
+
+        # insert directories, ordered by name depth
         for d in sorted(dirs, key=lambda x:len(x[-1].split("/"))):
             (user, group, size) = d[1:4]
             permission = d[0][1:]
             path = d[4].lstrip(".")
+
+            # we already created the root directory, so ignore any
+            # entry for it
             if len(path) == 0:
-                # we create the root directory as a special case
-                path = "/"
-                tf_obj = Target_File.objects.create(
-                        target = target_obj,
-                        path = path,
-                        size = size,
-                        inodetype = Target_File.ITYPE_DIRECTORY,
-                        permission = permission,
-                        owner = user,
-                        group = group,
-                        )
-                tf_obj.directory = tf_obj
-                tf_obj.save()
                 continue
+
             parent_path = "/".join(path.split("/")[:len(path.split("/")) - 1])
             if len(parent_path) == 0:
                 parent_path = "/"