Exception from backslash followed by space in field key

Specifications

• Client Version: 1.44.0
• InfluxDB Version: 2.7.6
• Platform: Linux

Code sample to reproduce problem

#!/usr/bin/env python3
from os import getenv

from influxdb_client import InfluxDBClient
from influxdb_client.client.write.point import Point
from influxdb_client.client.write_api import SYNCHRONOUS


influx_db_client = InfluxDBClient(
    url="http://localhost:8086",
    token=getenv("TEST_TOKEN"),
    org=getenv("TEST_ORG"),
)

write_api = influx_db_client.write_api(write_options=SYNCHRONOUS)

broken_line_protocol_line = Point.from_dict(
        {
            "measurement": "test-measurement-1",
            "tags": {"test-tag-key-X": "test-tag-value-X"},
            "fields": {r"this doesnt \ work": 666},
        }
    ).to_line_protocol()

result = write_api.write(
    getenv("TEST_BUCKET", "missing"),
    getenv("TEST_ORG"),
    broken_line_protocol_line,
)

print(f"result: {result}")

Expected behavior

Either that the data is accepted, or that I get a clear error message that a field keys with a single backslash followed by space is unsupported by Influx. I particularly expect that I get an exception from to_line_protocol rather than that it returns something that is invalid according to Influx and that Influx rejects with "invalid field format".

This problem also arises if giving the point object directly to write rather than going via to_line_protocol, this approach just makes it clear that it can return an invalid line protocol string.

Actual behavior

influxdb_client.rest.ApiException: (400)
Reason: Bad Request
HTTP response headers: HTTPHeaderDict({'Content-Type': 'application/json; charset=utf-8', 'X-Influxdb-Build': 'OSS', 'X-Influxdb-Version': 'v2.7.6', 'X-Platform-Error-Code': 'invalid', 'Date': 'Wed, 26 Jun 2024 13:28:23 GMT', 'Content-Length': '152'})
HTTP response body: {"code":"invalid","message":"unable to parse 'test-measurement-1,test-tag-key-X=test-tag-value-X this\\ doesnt\\ \\\\ work=666i': invalid field format"}

If I remove either the slash followed by space or the space, it works.

Additional info

AFAIK Influx doesn't support field keys that have a single backslash followed by a space? I intend to replace backslash-space with double-backslash-space on my end for backwards compatibility either way, but this tripped up four people at work when they upgraded and something that used to work (albeit by subtly turning a single into a double backslash) instead blew up with an exception.

influxdb-client 1.19.0 doesn't report an error and the values end up in the database, but it ends up with double backslashes for fields and tags.

Start with Point.from_dict and to_line_protocol, then trace how the field key is escaped before write sends the line protocol to InfluxDB. Reproduce the backslash-space case from the issue and make sure serialization either produces valid line protocol or raises a clear error before the request is sent.