Do specify filter="tar" when extracting tars

Situation is complicated is that when extracting .zip shutil.unpack_archive
would also pass it and would crash so we need to pass only when extracting
tar.  And also that kwargs option  was added in 3.12, started to be enforced
in 3.13 and in 3.14 would be required

Author: yarikoptic

heudiconv/parser.py

@@ -9,6 +9,7 @@
 import os.path as op
 import re
 import shutil
+import sys
 from types import ModuleType
 from typing import Optional
 
@@ -22,7 +23,18 @@
 
 _VCS_REGEX = r"%s\.(?:git|gitattributes|svn|bzr|hg)(?:%s|$)" % (op.sep, op.sep)
 
-_UNPACK_FORMATS = tuple(sum((x[1] for x in shutil.get_unpack_formats()), []))
+
+def _get_unpack_formats() -> dict[str, bool]:
+    """For each extension return if it is a tar"""
+    out = {}
+    for _, exts, d in shutil.get_unpack_formats():
+        for e in exts:
+            out[e] = bool(re.search(r"\btar\b", d.lower()))
+    return out
+
+
+_UNPACK_FORMATS = _get_unpack_formats()
+_TAR_UNPACK_FORMATS = tuple(k for k, is_tar in _UNPACK_FORMATS.items() if is_tar)
 
 
 @docstring_parameter(_VCS_REGEX)
@@ -114,7 +126,7 @@ def get_extracted_dicoms(fl: Iterable[str]) -> ItemsView[Optional[str], list[str
 
     # needs sorting to keep the generated "session" label deterministic
     for _, t in enumerate(sorted(fl)):
-        if not t.endswith(_UNPACK_FORMATS):
+        if not t.endswith(tuple(_UNPACK_FORMATS)):
             sessions[None].append(t)
             continue
 
@@ -127,7 +139,14 @@ def get_extracted_dicoms(fl: Iterable[str]) -> ItemsView[Optional[str], list[str
 
         # check content and sanitize permission bits before extraction
         os.chmod(tmpdir, mode=0o700)
-        shutil.unpack_archive(t, extract_dir=tmpdir)
+        # For tar (only!) starting with 3.12 we should provide filter
+        # (enforced in 3.14) on how to filter/safe-guard filenames.
+        kws = {}
+        if sys.version_info >= (3, 12) and t.endswith(_TAR_UNPACK_FORMATS):
+            # Allow for a user-workaround if would be desired
+            # see e.g. https://docs.python.org/3.12/library/tarfile.html#extraction-filters
+            kws["filter"] = os.environ.get("HEUDICONV_TAR_FILTER", "tar")
+        shutil.unpack_archive(t, extract_dir=tmpdir, **kws)
 
         archive_content = list(find_files(regex=".*", topdir=tmpdir))