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Title: One line description
HTTP path regex matching not working for paths with trailing slash

Description:

What issue is being seen? Describe what should be happening instead of
the bug, for example: Envoy should not crash, the expected value isn't
returned, etc.

I am trying use the regex /status/200(/.*)?$ that should behave as follows:
should match: /status/200, status/200/ (note trailing slash), /status/200/foo
should not match: /status/200foo

I see that the following route configuration in envoy is rejecting requests whose :path equals /status/200/ (includes trailing slash). Per the regex /status/200(/.*)?$, this request should be a match, but Envoy rejects it with a 404.

Route:

"routes": [
         {
          "match": {
           "headers": [
            {
             "name": ":method",
             "safe_regex_match": {
              "google_re2": {},
              "regex": ".*"
             }
            }
           ],
           "safe_regex": {
            "google_re2": {},
            "regex": "/status/200(/.*)?$"
           }

Repro steps:

Include sample requests, environment, etc. All data and inputs
required to reproduce the bug.

See above route configuration to repro.
Envoy version: envoyproxy/envoy-alpine:v1.17.1

I used Golang's regexp lib to verify the expected regex behavior: https://play.golang.org/p/GGppRHeEoW8

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Admin and Stats Output:

Include the admin output for the following endpoints: /stats,
/clusters, /routes, /server_info. For more information, refer to the
admin endpoint documentation.

I see downstream_rq_4xx in the inbound RDS configuration increment for requests with :path /status/200/.