fix: build StaticTable version-hint metadata locations with forward slashes

StaticTable._metadata_location_from_version_hint built the version-hint and
resolved metadata locations with os.path.join. Iceberg locations are URIs and
must always be forward-slash separated, but os.path.join uses the OS separator,
so on Windows it produced backslash-separated keys such as
s3://.../taxis\metadata\version-hint.text. That is an invalid object-store key,
which breaks the documented "pass the table root path" usage of
StaticTable.from_metadata on Windows.

Join the components with explicit forward slashes, matching how locations are
built elsewhere in pyiceberg (for example pyiceberg/table/locations.py). Behavior
is unchanged on POSIX. The now-unused os import is removed.

Add an OS-independent regression test that swaps os.path.join for the Windows
join so the metadata location is asserted to stay a valid forward-slash URI on
any platform (the existing test only exercised local temp paths, which use the
POSIX separator on Linux CI and never caught this).

Related: #2477

Author: anxkhn

pyiceberg/table/__init__.py

@@ -18,7 +18,6 @@
 
 import itertools
 import logging
-import os
 import random
 import time
 import uuid
@@ -1963,19 +1962,20 @@ def refresh(self) -> Table:
 
     @classmethod
     def _metadata_location_from_version_hint(cls, metadata_location: str, properties: Properties = EMPTY_DICT) -> str:
-        version_hint_location = os.path.join(metadata_location, "metadata", "version-hint.text")
+        metadata_dir = f"{metadata_location.rstrip('/')}/metadata"
+        version_hint_location = f"{metadata_dir}/version-hint.text"
         io = load_file_io(properties=properties, location=version_hint_location)
         file = io.new_input(version_hint_location)
 
         with file.open() as stream:
             content = stream.read().decode("utf-8")
 
         if content.endswith(".metadata.json"):
-            return os.path.join(metadata_location, "metadata", content)
+            return f"{metadata_dir}/{content}"
         elif content.isnumeric():
-            return os.path.join(metadata_location, "metadata", f"v{content}.metadata.json")
+            return f"{metadata_dir}/v{content}.metadata.json"
         else:
-            return os.path.join(metadata_location, "metadata", f"{content}.metadata.json")
+            return f"{metadata_dir}/{content}.metadata.json"
 
     @classmethod
     def from_metadata(cls, metadata_location: str, properties: Properties = EMPTY_DICT) -> StaticTable:

tests/table/test_init.py

@@ -590,6 +590,49 @@ def test_static_table_version_hint_same_as_table(
         assert static_table.metadata == table_v2.metadata
 
 
+@pytest.mark.parametrize(
+    "version_hint_content, expected_metadata_file",
+    [
+        ("v3.metadata.json", "v3.metadata.json"),
+        ("3", "v3.metadata.json"),
+        ("some-uuid", "some-uuid.metadata.json"),
+    ],
+)
+def test_static_table_version_hint_location_uses_forward_slashes(
+    version_hint_content: str, expected_metadata_file: str, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    # Iceberg locations are URIs and must always be forward-slash separated, regardless of the host OS.
+    table_root = "s3://warehouse/wh/nyc.db/taxis"
+    requested_locations: list[str] = []
+
+    class _FakeStream:
+        def __enter__(self) -> "_FakeStream":
+            return self
+
+        def __exit__(self, *args: Any) -> None:
+            return None
+
+        def read(self, size: int = 0) -> bytes:
+            return version_hint_content.encode("utf-8")
+
+    class _FakeInputFile:
+        def open(self, seekable: bool = True) -> "_FakeStream":
+            return _FakeStream()
+
+    class _FakeFileIO:
+        def new_input(self, location: str) -> "_FakeInputFile":
+            requested_locations.append(location)
+            return _FakeInputFile()
+
+    monkeypatch.setattr("pyiceberg.table.load_file_io", lambda *args, **kwargs: _FakeFileIO())
+
+    resolved_location = StaticTable._metadata_location_from_version_hint(table_root)
+
+    assert requested_locations == [f"{table_root}/metadata/version-hint.text"]
+    assert resolved_location == f"{table_root}/metadata/{expected_metadata_file}"
+    assert "\\" not in resolved_location
+
+
 def test_static_table_io_does_not_exist(metadata_location: str) -> None:
     with pytest.raises(ValueError):
         StaticTable.from_metadata(metadata_location, {PY_IO_IMPL: "pyiceberg.does.not.exist.FileIO"})