URL parameters from string URLs get doubly URL encoded

[jhominal]

Currently, I have an issue that prevents usage of the last version of httpx:

• I have a URL stored as an str object, that I wish to process;
• That URL contains a query, with a query parameter that is itself an URL containing query parameters. In order to make the specification of that str possible, the query parameters from the URL need to be encoded. However, as slashes are not requiredhave naturally been re-encoded, in which slashes have not been encoded (http://host/path?sub_url=https://other?a%3Db%26c%3Dd);
• httpx double encodes the already existing % characters, sending the http://host/path?sub_url=https:%2F%2Fother?a%253Db%2526c%253Dd - and the server finds itself processing doubly-encoded URL parameters.

I am not really bothered by the fact that slashes get URL-encoded (unlike #2864)

However, I guess my issue is the same as #2863 - I do not think that the % character in my context should be URL encoded.

[Ultroncn]

I checked the exact URL in your question on HTTPX 0.28.1. Passing it directly as the request URL preserves the existing escapes:

import httpx

url = "http://host/path?sub_url=https://other?a%3Db%26c%3Dd"
request = httpx.Request("GET", url)
assert str(request.url) == url
assert request.url.params["sub_url"] == "https://other?a=b&c=d"

This only constructs a request; no network call is involved. The URL tests also cover preservation of existing percent encoding.

There are two different input contracts: a complete, already-encoded URL can be supplied as above; values supplied through params= should be decoded logical values:

request = httpx.Request(
    "GET", "http://host/path",
    params={"sub_url": "https://other?a=b&c=d"},
)
assert request.url.params["sub_url"] == "https://other?a=b&c=d"

Passing an already-quoted value inside that dictionary introduces another encoding layer: % itself is then data to encode. This does not prove that was the cause in your older version, but the complete request-construction call and installed HTTPX version would distinguish a version regression from an extra params=/quoting step.