Parameter URL encoding is inconsistent with Feign 10

[seanstephenson-taulia]

I have a project that works under Feign 9 but is broken in Feign 10.

Consider the following example:

interface ExampleClient {
  @RequestLine("GET /search?text={text}")
  void search(@Param("text") String text);
}

Most values are automatically encoded when passed through. But if there is a value that appears to match a pre-encoded hex value it will not be encoded correctly.

text = %example% works correctly
text = %address% is not encoded correctly

I assume the problem is that the %ad in address could be interpreted as a hex value so feign is attempting to infer that the value is already encoded. The issue is that there is no reliable way to pass through a value like %address% that looks like a hex value but actually is not.

[seanstephenson-taulia]

Another note: I've attempted to work around the issue by encoding all parameters before submitting them to the client (i.e. "%25address"), but then the values that don't appear to be hex values become double encoded.

[kdavisk6]

@seanstephenson-taulia

This does appear to be a side-effect of the changes around recognizing already pct-encoded values. I've categorized this as a bug and a regression issue. We appreciate any additional context and/or test cases you can provide.

[seanstephenson-taulia]

I added a reproducible test case here.
https://github.com/seanstephenson-taulia/openfeign-url-encoding-issue

(thanks to https://github.com/sguillope whose project I borrowed as a starting point)