gh-130379: Fix incorrect zipapp logic to avoid including the target in itself

Lib/test/test_zipapp.py

@@ -89,6 +89,20 @@ def skip_pyc_files(path):
             self.assertIn('test.py', z.namelist())
             self.assertNotIn('test.pyc', z.namelist())
 
+    def test_create_archive_self_insertion(self):
+        # When creating an archive, we shouldn't
+        # include the archive in the lis of files to add.
+        source = self.tmpdir
+        (source / '__main__.py').touch()
+        (source / 'test.py').touch()
+        target = self.tmpdir / 'target.pyz'
+
+        zipapp.create_archive(source, target)
+        with zipfile.ZipFile(target, 'r') as z:
+            self.assertEqual(len(z.namelist()), 2)
+            self.assertIn('__main__.py', z.namelist())
+            self.assertIn('test.py', z.namelist())
+
     def test_create_archive_filter_exclude_dir(self):
         # Test packing a directory and using a filter to exclude a
         # subdirectory (ensures that the path supplied to include

Lib/zipapp.py

@@ -131,14 +131,18 @@ def create_archive(source, target=None, interpreter=None, main=None,
     elif not hasattr(target, 'write'):
         target = pathlib.Path(target)
 
+    # Create the list of files to add to the archive now, in case
+    # the target is being created in the source directory - we
+    # don't want the target being added to itself
+    files_to_add = sorted(source.rglob('*'))
     with _maybe_open(target, 'wb') as fd:
         _write_file_prefix(fd, interpreter)
         compression = (zipfile.ZIP_DEFLATED if compressed else
                        zipfile.ZIP_STORED)
         with zipfile.ZipFile(fd, 'w', compression=compression) as z:
-            for child in sorted(source.rglob('*')):
+            for child in files_to_add:
                 arcname = child.relative_to(source)
-                if filter is None or filter(arcname) and child.resolve() != arcname.resolve():
+                if filter is None or filter(arcname):
                     z.write(child, arcname.as_posix())
             if main_py:
                 z.writestr('__main__.py', main_py.encode('utf-8'))

Misc/NEWS.d/next/Library/2025-02-24-14-46-20.gh-issue-130379.lsef7A.rst

@@ -0,0 +1 @@
+The zipapp module now calculates the list of files to be added to the archive before creating the archive. This avoids accidentally including the target when it is being created in the source directory.