Changes to FAT back-end (#580)

config/dpkg/changelog

@@ -1,5 +1,5 @@
-dfvfs (20251125-1) unstable; urgency=low
+dfvfs (20260207-1) unstable; urgency=low
 
   * Auto-generated
 
- -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Tue, 25 Nov 2025 13:08:38 +0100
+ -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Sat, 07 Feb 2026 09:33:49 +0100

dfvfs/__init__.py

@@ -6,4 +6,4 @@
 types and file formats.
 """
 
-__version__ = '20251125'
+__version__ = '20260207'

dfvfs/vfs/fat_directory.py

@@ -31,13 +31,12 @@ def _EntriesGenerator(self):
     location = getattr(self.path_spec, 'location', None)
 
     for fsfat_sub_file_entry in self._fsfat_file_entry.sub_file_entries:
-      directory_entry = fsfat_sub_file_entry.name
-
       if not location or location == self._file_system.PATH_SEPARATOR:
-        directory_entry = self._file_system.JoinPath([directory_entry])
+        directory_entry = self._file_system.JoinPath([
+            fsfat_sub_file_entry.name])
       else:
         directory_entry = self._file_system.JoinPath([
-            location, directory_entry])
+            location, fsfat_sub_file_entry.name])
 
       yield fat_path_spec.FATPathSpec(
           identifier=fsfat_sub_file_entry.identifier, location=directory_entry,

dfvfs/vfs/fat_file_system.py

@@ -79,17 +79,18 @@ def FileEntryExistsByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by identifier is faster than opening a file by location.
+    # Opening a file by identifier is faster than opening a file by location,
+    # but can fail in determining the VFAT long file name.
     fsfat_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
 
     try:
-      if identifier is not None:
+      if location is not None:
+        fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
+      elif identifier is not None:
         fsfat_file_entry = self._fsfat_volume.get_file_entry_by_identifier(
             identifier)
-      elif location is not None:
-        fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
 
     except IOError as exception:
       raise errors.BackEndError(exception)
@@ -108,7 +109,8 @@ def GetFileEntryByPathSpec(self, path_spec):
     Raises:
       BackEndError: if the file entry cannot be opened.
     """
-    # Opening a file by identifier is faster than opening a file by location.
+    # Opening a file by identifier is faster than opening a file by location,
+    # but can fail in determining the VFAT long file name.
     fsfat_file_entry = None
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
@@ -121,11 +123,11 @@ def GetFileEntryByPathSpec(self, path_spec):
           fsfat_file_entry=fsfat_file_entry, is_root=True)
 
     try:
-      if identifier is not None:
+      if location is not None:
+        fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
+      elif identifier is not None:
         fsfat_file_entry = self._fsfat_volume.get_file_entry_by_identifier(
             identifier)
-      elif location is not None:
-        fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
 
     except IOError as exception:
       raise errors.BackEndError(exception)
@@ -150,15 +152,16 @@ def GetFATFileEntryByPathSpec(self, path_spec):
       PathSpecError: if the path specification is missing location and
           identifier.
     """
-    # Opening a file by identifier is faster than opening a file by location.
+    # Opening a file by identifier is faster than opening a file by location,
+    # but can fail in determining the VFAT long file name.
     location = getattr(path_spec, 'location', None)
     identifier = getattr(path_spec, 'identifier', None)
 
-    if identifier is not None:
+    if location is not None:
+      fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
+    elif identifier is not None:
       fsfat_file_entry = self._fsfat_volume.get_file_entry_by_identifier(
           identifier)
-    elif location is not None:
-      fsfat_file_entry = self._fsfat_volume.get_file_entry_by_path(location)
     else:
       raise errors.PathSpecError(
           'Path specification missing location and identifier.')

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "dfvfs"
-version = "20251125"
+version = "20260207"
 description = "Digital Forensics Virtual File System (dfVFS)"
 maintainers = [
     { name = "Log2Timeline maintainers", email = "log2timeline-maintainers@googlegroups.com" },