Sync contrib/tools/python3 layout with upstream

* Move src/ subdir contents to the top of the layout
* Rename self-written lib -> lib2 to avoid CaseFolding warning from the VCS
* Regenerate contrib/libs/python proxy-headers accordingly
4ccc62ac1511abcf0fed14ccade38e984e088f1e

1 files changed, 181 insertions, 0 deletions

diff --git a/contrib/tools/python3/Lib/zoneinfo/_tzpath.py b/contrib/tools/python3/Lib/zoneinfo/_tzpath.py
new file mode 100644
index 00000000000..5db17bea045
--- /dev/null
+++ b/contrib/tools/python3/Lib/zoneinfo/_tzpath.py
@@ -0,0 +1,181 @@
+import os
+import sysconfig
+
+
+def _reset_tzpath(to=None, stacklevel=4):
+    global TZPATH
+
+    tzpaths = to
+    if tzpaths is not None:
+        if isinstance(tzpaths, (str, bytes)):
+            raise TypeError(
+                f"tzpaths must be a list or tuple, "
+                + f"not {type(tzpaths)}: {tzpaths!r}"
+            )
+
+        if not all(map(os.path.isabs, tzpaths)):
+            raise ValueError(_get_invalid_paths_message(tzpaths))
+        base_tzpath = tzpaths
+    else:
+        env_var = os.environ.get("PYTHONTZPATH", None)
+        if env_var is None:
+            env_var = sysconfig.get_config_var("TZPATH")
+        base_tzpath = _parse_python_tzpath(env_var, stacklevel)
+
+    TZPATH = tuple(base_tzpath)
+
+
+def reset_tzpath(to=None):
+    """Reset global TZPATH."""
+    # We need `_reset_tzpath` helper function because it produces a warning,
+    # it is used as both a module-level call and a public API.
+    # This is how we equalize the stacklevel for both calls.
+    _reset_tzpath(to)
+
+
+def _parse_python_tzpath(env_var, stacklevel):
+    if not env_var:
+        return ()
+
+    raw_tzpath = env_var.split(os.pathsep)
+    new_tzpath = tuple(filter(os.path.isabs, raw_tzpath))
+
+    # If anything has been filtered out, we will warn about it
+    if len(new_tzpath) != len(raw_tzpath):
+        import warnings
+
+        msg = _get_invalid_paths_message(raw_tzpath)
+
+        warnings.warn(
+            "Invalid paths specified in PYTHONTZPATH environment variable. "
+            + msg,
+            InvalidTZPathWarning,
+            stacklevel=stacklevel,
+        )
+
+    return new_tzpath
+
+
+def _get_invalid_paths_message(tzpaths):
+    invalid_paths = (path for path in tzpaths if not os.path.isabs(path))
+
+    prefix = "\n    "
+    indented_str = prefix + prefix.join(invalid_paths)
+
+    return (
+        "Paths should be absolute but found the following relative paths:"
+        + indented_str
+    )
+
+
+def find_tzfile(key):
+    """Retrieve the path to a TZif file from a key."""
+    _validate_tzfile_path(key)
+    for search_path in TZPATH:
+        filepath = os.path.join(search_path, key)
+        if os.path.isfile(filepath):
+            return filepath
+
+    return None
+
+
+_TEST_PATH = os.path.normpath(os.path.join("_", "_"))[:-1]
+
+
+def _validate_tzfile_path(path, _base=_TEST_PATH):
+    if os.path.isabs(path):
+        raise ValueError(
+            f"ZoneInfo keys may not be absolute paths, got: {path}"
+        )
+
+    # We only care about the kinds of path normalizations that would change the
+    # length of the key - e.g. a/../b -> a/b, or a/b/ -> a/b. On Windows,
+    # normpath will also change from a/b to a\b, but that would still preserve
+    # the length.
+    new_path = os.path.normpath(path)
+    if len(new_path) != len(path):
+        raise ValueError(
+            f"ZoneInfo keys must be normalized relative paths, got: {path}"
+        )
+
+    resolved = os.path.normpath(os.path.join(_base, new_path))
+    if not resolved.startswith(_base):
+        raise ValueError(
+            f"ZoneInfo keys must refer to subdirectories of TZPATH, got: {path}"
+        )
+
+
+del _TEST_PATH
+
+
+def available_timezones():
+    """Returns a set containing all available time zones.
+
+    .. caution::
+
+        This may attempt to open a large number of files, since the best way to
+        determine if a given file on the time zone search path is to open it
+        and check for the "magic string" at the beginning.
+    """
+    from importlib import resources
+
+    valid_zones = set()
+
+    # Start with loading from the tzdata package if it exists: this has a
+    # pre-assembled list of zones that only requires opening one file.
+    try:
+        with resources.files("tzdata").joinpath("zones").open("r") as f:
+            for zone in f:
+                zone = zone.strip()
+                if zone:
+                    valid_zones.add(zone)
+    except (ImportError, FileNotFoundError):
+        pass
+
+    def valid_key(fpath):
+        try:
+            with open(fpath, "rb") as f:
+                return f.read(4) == b"TZif"
+        except Exception:  # pragma: nocover
+            return False
+
+    for tz_root in TZPATH:
+        if not os.path.exists(tz_root):
+            continue
+
+        for root, dirnames, files in os.walk(tz_root):
+            if root == tz_root:
+                # right/ and posix/ are special directories and shouldn't be
+                # included in the output of available zones
+                if "right" in dirnames:
+                    dirnames.remove("right")
+                if "posix" in dirnames:
+                    dirnames.remove("posix")
+
+            for file in files:
+                fpath = os.path.join(root, file)
+
+                key = os.path.relpath(fpath, start=tz_root)
+                if os.sep != "/":  # pragma: nocover
+                    key = key.replace(os.sep, "/")
+
+                if not key or key in valid_zones:
+                    continue
+
+                if valid_key(fpath):
+                    valid_zones.add(key)
+
+    if "posixrules" in valid_zones:
+        # posixrules is a special symlink-only time zone where it exists, it
+        # should not be included in the output
+        valid_zones.remove("posixrules")
+
+    return valid_zones
+
+
+class InvalidTZPathWarning(RuntimeWarning):
+    """Warning raised if an invalid path is specified in PYTHONTZPATH."""
+
+
+TZPATH = ()
+_reset_tzpath(stacklevel=5)