Wrong name tag for HTTP metrics from redirects

[na--]

When you make HTTP requests with redirects, the name tag in the generated metrics is wrong - it contains the original URL... For example, if you run the following script:

import http from 'k6/http';

export default function () {
    http.get("https://httpbin.test.k6.io/redirect-to?url=https%3A%2F%2Fhttpbin.test.k6.io%2Fanything");
}

with k6 run --out json=results.json script.js, and then filter the generated metrics with to get the url tags with jq '. | select(.type=="Point" and .metric == "http_reqs") | .data.tags.url' results.json, you'd get this:

"https://httpbin.test.k6.io/redirect-to?url=https%3A%2F%2Fhttpbin.test.k6.io%2Fanything"
"https://httpbin.test.k6.io/anything"

which is perfectly fine, but if you get the name tag with jq '. | select(.type=="Point" and .metric == "http_reqs") | .data.tags.name' results.json, you'd get:

"https://httpbin.test.k6.io/redirect-to?url=https%3A%2F%2Fhttpbin.test.k6.io%2Fanything"
"https://httpbin.test.k6.io/redirect-to?url=https%3A%2F%2Fhttpbin.test.k6.io%2Fanything"

If we had explicitly specified such a name tag, or anything other in the http.get() params, it would be fine. But in this case, the result of these 2 commands should have been identical...

The consequence of this in the cloud is even worse, since the name tag is used for request grouping, it looks like this:

[na--]

Moved it back to v0.28.0, since the fix turned out to be more tricky than expected, and blurred the line between a bugfix and a minor breaking change... 😞