Changes for empty APFS volumes (#660)

config/dpkg/changelog

@@ -1,5 +1,5 @@
-dfvfs (20220419-1) unstable; urgency=low
+dfvfs (20220430-1) unstable; urgency=low
 
   * Auto-generated
 
- -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Tue, 19 Apr 2022 11:17:49 +0200
+ -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Sat, 30 Apr 2022 06:49:30 +0200

dfvfs/__init__.py

@@ -6,4 +6,4 @@
 storage media types and file formats.
 """
 
-__version__ = '20220419'
+__version__ = '20220430'

dfvfs/helpers/volume_scanner.py

@@ -509,6 +509,12 @@ def _ScanFileSystem(self, scan_node, base_path_specs):
     if not scan_node or not scan_node.path_spec:
       raise errors.ScannerError('Invalid or missing file system scan node.')
 
+    if scan_node.type_indicator == definitions.TYPE_INDICATOR_APFS:
+      # Note that APFS can have a volume without a root directory.
+      file_entry = resolver.Resolver.OpenFileEntry(scan_node.path_spec)
+      if not file_entry:
+        return
+
     base_path_specs.append(scan_node.path_spec)
 
   def _ScanSource(self, source_path):

dfvfs/vfs/apfs_file_system.py

@@ -127,27 +127,29 @@ def GetFileEntryByPathSpec(self, path_spec):
 
     if (location == self.LOCATION_ROOT or
         identifier == self.ROOT_DIRECTORY_IDENTIFIER):
+      is_root = True
+      # Note that APFS can have a volume without a root directory.
       fsapfs_file_entry = self._fsapfs_volume.get_root_directory()
-      return apfs_file_entry.APFSFileEntry(
-          self._resolver_context, self, path_spec,
-          fsapfs_file_entry=fsapfs_file_entry, is_root=True)
 
-    try:
-      if location is not None:
-        fsapfs_file_entry = self._fsapfs_volume.get_file_entry_by_path(location)
-      elif identifier is not None:
-        fsapfs_file_entry = self._fsapfs_volume.get_file_entry_by_identifier(
-            identifier)
-
-    except IOError as exception:
-      raise errors.BackEndError(exception)
+    else:
+      is_root = False
+      try:
+        if location is not None:
+          fsapfs_file_entry = self._fsapfs_volume.get_file_entry_by_path(
+              location)
+        elif identifier is not None:
+          fsapfs_file_entry = self._fsapfs_volume.get_file_entry_by_identifier(
+              identifier)
+
+      except IOError as exception:
+        raise errors.BackEndError(exception)
 
     if fsapfs_file_entry is None:
       return None
 
     return apfs_file_entry.APFSFileEntry(
         self._resolver_context, self, path_spec,
-        fsapfs_file_entry=fsapfs_file_entry)
+        fsapfs_file_entry=fsapfs_file_entry, is_root=is_root)
 
   def GetAPFSFileEntryByPathSpec(self, path_spec):
     """Retrieves the APFS file entry for a path specification.
@@ -182,7 +184,7 @@ def GetRootFileEntry(self):
     """Retrieves the root file entry.
 
     Returns:
-      APFSFileEntry: file entry.
+      APFSFileEntry: file entry or None if not available.
     """
     path_spec = apfs_path_spec.APFSPathSpec(
         location=self.LOCATION_ROOT, identifier=self.ROOT_DIRECTORY_IDENTIFIER,