MemPalace/mempalace · error · ValueError

contains null bytes

Error message

{field_name} contains null bytes

What it means

Raised by sanitize_name() when the supplied name contains a NUL byte (\x00). NUL bytes are invalid in filesystem paths and terminate C strings in underlying storage engines (SQLite, ChromaDB), so any name containing one is rejected before storage. This usually indicates corrupted input or binary data leaking into a text field.

Solutions

1. Strip or reject NUL bytes at the source: name.replace("\x00", "") if lossy cleanup is acceptable
2. Find where the binary data entered the pipeline (file decode mode, socket read) and fix the decoding
3. Treat the presence of \x00 in a name as a bug in the upstream producer, not something to sanitize away silently

Example fix

# before
name = raw_bytes.decode("utf-8", errors="ignore")   # may retain \x00

# after
name = raw_bytes.decode("utf-8", errors="strict").replace("\x00", "")

# Reject binary-contaminated names before the call:
if not isinstance(name, str) or "\x00" in name:
    raise SystemExit("name must be NUL-free text")

def is_nul_free(value: str) -> bool:
    return isinstance(value, str) and "\x00" not in value

try:
    safe = sanitize_name(name)
except ValueError as exc:
    if "null bytes" in str(exc):
        safe = sanitize_name(name.replace("\x00", ""))
    else:
        raise

When it happens

Trigger: Passing a name containing \x00 — typically from decoding binary data, truncated/corrupted UTF-8, or a test fixture embedding raw bytes.

Common situations: Reading names from a binary or mis-decoded source; data corrupted in transit; fuzzing/security testing payloads embedded in tool arguments.

Related errors

• contains invalid path characters
• content contains null bytes
• contains invalid characters
• exceeds maximum length of characters
• must be a non-empty string

AI-assisted analysis of MemPalace/mempalace@06cb6987f0 (2026-08-15). Data as JSON: /api/errors/727de785781f4ec9. Report an issue: GitHub.

Appendix: source

Thrown at mempalace/config.py:92

    """Validate and sanitize a wing/room/entity name.

    Raises ValueError if the name is invalid.
    """
    if not isinstance(value, str) or not value.strip():
        raise ValueError(f"{field_name} must be a non-empty string")

    value = value.strip()

    if len(value) > MAX_NAME_LENGTH:
        raise ValueError(f"{field_name} exceeds maximum length of {MAX_NAME_LENGTH} characters")

    # Block path traversal
    if ".." in value or "/" in value or "\\" in value:
        raise ValueError(f"{field_name} contains invalid path characters")

    # Block null bytes
    if "\x00" in value:
        raise ValueError(f"{field_name} contains null bytes")

    # Enforce safe character set
    if not _SAFE_NAME_RE.match(value):
        raise ValueError(f"{field_name} contains invalid characters")

    return value


def sanitize_kg_value(value: str, field_name: str = "value") -> str:
    """Validate a knowledge-graph entity name (subject or object).

    More permissive than sanitize_name — allows punctuation like commas,
    colons, and parentheses that are common in natural-language KG values.
    Only blocks null bytes and over-length strings.

    Not used for wing/room names (which have filesystem constraints) or
    predicates (which should be simple relationship identifiers).
    """

View on GitHub (pinned to 06cb6987f0)