Mark superseded commits honestly instead of skipped (closes #152)

Gitea cancels an in-flight run when a newer commit lands on the same
branch and records the cancellation as `failure` / "Has been
cancelled". The workflow rewrote that to `skipped`, but Gitea's
Combine() folds `skipped` into `success`, so the combined-status API
returned green for a commit nothing had ever tested. Rewrite it to
`failure` / "Superseded by a newer commit; never tested" instead:
red-but-honest, and never `pending`, which would block the commit
forever.

Re-running the superseded commit would have been better still, but is
not reachable on this Gitea (1.25.4): its API exposes no rerun
endpoint, workflow dispatch takes a ref rather than a SHA, and every
replay would be a full uncached build with no bound on how many pile
up behind a burst of merges.

The step also stops hardcoding its status context: the logic moves into
script/ci-mark-superseded, which derives the context from the workflow
name, job id and event, and fails loudly when no status on the commit
being built carries that context, so renaming the workflow or the job
cannot silently disable the rewrite. The derivation is not byte-exact
with Gitea's own rule -- Gitea uses the job's display `name:` where the
runner exports the job id -- so adding a `name:` to the job turns every
push red rather than quietly doing nothing; the script header says so,
because that loud failure is the point. That is item 2 of
#147; item 1 there is
untouched.

Nothing about the walk may fail quietly, since the script exists to
stop CI lying quietly. An ANCESTOR_LIMIT that is set but not a positive
integer aborts instead of passing an unusable value to git and
discarding the error; the root-commit case is detected explicitly so
every other rev-list failure aborts too; and per-ancestor status reads
carry the same `--retry 3 --max-time 30` as the head-commit read and
abort on failure rather than losing curl's exit status through a pipe.

Tests drive the script against a fake Gitea covering the cancelled,
laundered-skipped, genuinely-failed, passing and renamed cases, an
unparseable ANCESTOR_LIMIT and an ancestor whose status read answers
HTTP 500, so jq joins the builder image to run them.

README.md

@@ -1003,14 +1003,7 @@ Every limiter here — receiver, login, and password change — identifies
 the client the same way, through one shared key function: the
 connection's own address, unless the peer is listed in
 `TRUSTED_PROXIES`, in which case the forwarded client address is used
-instead. That address becomes a bucket by family: IPv4 keys on the full
-address, IPv6 on its `/64` prefix. A routed `/64` is the normal
-residential and mobile IPv6 allocation, so keying IPv6 per address would
-let one subscriber rotate source addresses and mint a fresh bucket per
-request, evading these limits at the network layer without spoofing
-anything; the cost is that distinct clients inside one `/64` share a
-bucket. IPv4-mapped addresses (`::ffff:1.2.3.4`) key as the IPv4 address
-they carry. See [Trusted proxies](#trusted-proxies). Deployed without that
+instead. See [Trusted proxies](#trusted-proxies). Deployed without that
 variable set, a client behind a reverse proxy shares one bucket with
 every other client behind the same proxy. Set `TRUSTED_PROXIES` to the
 proxy's address to get per-client limits back. What the shared bucket

internal/middleware/ratelimit.go

@@ -48,12 +48,6 @@ const (
 	// bound every request pays a walk proportional to whatever the
 	// client sent.
 	maxForwardedHops = 64
-
-	// ipv6BucketBits is the prefix length IPv6 clients are bucketed
-	// on. A routed /64 is the normal residential and mobile
-	// allocation, so it is the unit an attacker gets addresses in
-	// and therefore the unit worth limiting.
-	ipv6BucketBits = 64
 )
 
 // normalizeAddr strips the IPv4-in-IPv6 wrapper and any zone from
@@ -62,40 +56,6 @@ func normalizeAddr(addr netip.Addr) netip.Addr {
 	return addr.Unmap().WithZone("")
 }
 
-// bucketKey is the rate-limit bucket identity of a client address.
-// IPv4 keys on the full address; IPv6 keys on its /64 prefix,
-// because keying IPv6 per /128 lets one ordinary subscriber rotate
-// source addresses inside its own routed /64 and mint a fresh bucket
-// per request — evading every limiter here at the network layer,
-// with no spoofing and nothing to detect.
-//
-// An IPv4-mapped address (::ffff:1.2.3.4) is keyed as the IPv4
-// address it carries, never masked to a /64: mapped form all shares
-// the ::ffff:0:0/96 prefix, so masking would collapse every IPv4
-// client reaching a proxy that emits it into one bucket. Callers
-// pass addresses through normalizeAddr, which already unmaps; the
-// unmap here keeps the property true of the key function itself.
-//
-// The two families cannot collide: an IPv4 key is a bare dotted
-// quad, and an IPv6 key always carries a "/64" suffix.
-func bucketKey(addr netip.Addr) string {
-	addr = addr.Unmap()
-
-	if addr.Is4() {
-		return addr.String()
-	}
-
-	// Prefix errors only on a negative bit count, on over 32 bits
-	// for an IPv4 address, or on over 128 for IPv6. The count here
-	// is the constant 64 and the IPv4 case returned above, so the
-	// error is unreachable. (The zero Addr does not error either: it
-	// yields the zero Prefix. Neither call site can produce one,
-	// since both parse the address first.)
-	prefix, _ := addr.Prefix(ipv6BucketBits)
-
-	return prefix.String()
-}
-
 // isTrustedProxy reports whether addr belongs to a network the
 // operator listed in TRUSTED_PROXIES. The list is empty by default,
 // so by default nothing is trusted.
@@ -183,9 +143,6 @@ func (m *Middleware) forwardedClientAddr(
 // another client's bucket, by picking an X-Forwarded-For value —
 // which makes every limit here decorative against a deliberate
 // attacker.
-//
-// The address that identifies the client is then reduced to a bucket
-// by bucketKey: full address for IPv4, /64 prefix for IPv6.
 func (m *Middleware) rateLimitKey(r *http.Request) (string, error) {
 	return m.clientKey(r), nil
 }
@@ -195,25 +152,23 @@ func (m *Middleware) clientKey(r *http.Request) string {
 	peer, err := netip.ParseAddr(ipFromHostPort(r.RemoteAddr))
 	if err != nil {
 		// Not an address we can reason about; key on the raw
-		// value, the most specific identity left. Distinct
-		// RemoteAddr values stay in distinct buckets, so this
-		// path cannot silently collapse unrelated clients
-		// together. On a Unix-socket listener every peer
-		// carries the same RemoteAddr and so shares one bucket,
-		// which is the fail-closed direction.
+		// value, the most specific identity left. On a
+		// Unix-socket listener every peer carries the same
+		// RemoteAddr and so shares one bucket, which is the
+		// fail-closed direction.
 		return r.RemoteAddr
 	}
 
 	peer = normalizeAddr(peer)
 	if !m.isTrustedProxy(peer) {
-		return bucketKey(peer)
+		return peer.String()
 	}
 
 	if addr, ok := m.forwardedClientAddr(r); ok {
-		return bucketKey(addr)
+		return addr.String()
 	}
 
-	return bucketKey(peer)
+	return peer.String()
 }
 
 // tooManyRequests returns the 429 handler used by the login,

internal/middleware/ratelimit_test.go

@@ -15,7 +15,6 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 	"sneak.berlin/go/webhooker/internal/config"
 	"sneak.berlin/go/webhooker/internal/middleware"
 )
@@ -371,30 +370,6 @@ const (
 	headerXFF  = "X-Forwarded-For"
 	headerReal = "X-Real-IP"
 	headerTrue = "True-Client-IP"
-
-	// clientIPv4 is the sample IPv4 client address these tests key
-	// on, both directly and in IPv4-mapped form. clientIPv4Alt is
-	// its neighbour, used to show the two do not share a bucket.
-	clientIPv4    = "198.51.100.7"
-	clientIPv4Alt = "198.51.100.8"
-
-	// clientIPv6 and clientIPv6Same are two addresses inside one
-	// routed /64, so both must key on clientBucketV6.
-	// clientIPv6Other is a different allocation and must key on
-	// clientOtherBucketV6.
-	clientIPv6          = "2001:db8:1:2:3:4:5:6"
-	clientIPv6Same      = "2001:db8:1:2:aaaa:bbbb:cccc:dddd"
-	clientIPv6Other     = "2001:db8:1:3::1"
-	clientBucketV6      = "2001:db8:1:2::/64"
-	clientOtherBucketV6 = "2001:db8:1:3::/64"
-
-	// trustedProxyCIDR is the proxy network the forwarded-path
-	// tests configure, and trustedPeer an address inside it. A
-	// production deployment is required to run behind a reverse
-	// proxy with TRUSTED_PROXIES set, so this is the shape the
-	// bucketing has to hold in.
-	trustedProxyCIDR = "10.0.0.0/8"
-	trustedPeer      = "10.0.0.1:44444"
 )
 
 // assertSharedBucket drives the login limiter from peer with the
@@ -483,8 +458,8 @@ func TestRateLimitKey_SingleValuedHeadersIgnoredFromTrustedPeer(
 			t.Parallel()
 
 			assertSharedBucket(
-				t, trustedProxies(trustedProxyCIDR),
-				trustedPeer,
+				t, trustedProxies("10.0.0.0/8"),
+				"10.0.0.1:44444",
 				func(i int) map[string]string {
 					return map[string]string{
 						header: fmt.Sprintf(
@@ -520,8 +495,8 @@ func TestRateLimitKey_MalformedRightmostHopFallsBackToPeer(
 			t.Parallel()
 
 			assertSharedBucket(
-				t, trustedProxies(trustedProxyCIDR),
-				trustedPeer,
+				t, trustedProxies("10.0.0.0/8"),
+				"10.0.0.1:44444",
 				func(i int) map[string]string {
 					return map[string]string{
 						headerXFF: fmt.Sprintf(
@@ -547,13 +522,13 @@ func TestRateLimitKey_ForwardedHonouredFromTrustedPeer(
 	t.Parallel()
 
 	m := rateLimitMiddleware(t, &config.Config{
-		TrustedProxies: trustedProxies(trustedProxyCIDR),
+		TrustedProxies: trustedProxies("10.0.0.0/8"),
 	})
 	handler := m.LoginRateLimit()(okHandler())
 
-	const peer = trustedPeer
+	const peer = "10.0.0.1:44444"
 
-	first := map[string]string{headerXFF: clientIPv4}
+	first := map[string]string{headerXFF: "198.51.100.7"}
 
 	for range middleware.LoginRateLimitConst {
 		postWithHeaders(handler, peer, loginPath, first)
@@ -567,7 +542,7 @@ func TestRateLimitKey_ForwardedHonouredFromTrustedPeer(
 
 	w = postWithHeaders(
 		handler, peer, loginPath,
-		map[string]string{headerXFF: clientIPv4Alt},
+		map[string]string{headerXFF: "198.51.100.8"},
 	)
 	assert.Equal(
 		t, http.StatusOK, w.Code,
@@ -584,7 +559,7 @@ func TestRateLimitKey_ChainWalkSkipsClientPrepended(t *testing.T) {
 	t.Parallel()
 
 	assertSharedBucket(
-		t, trustedProxies(trustedProxyCIDR), trustedPeer,
+		t, trustedProxies("10.0.0.0/8"), "10.0.0.1:44444",
 		func(i int) map[string]string {
 			return map[string]string{
 				headerXFF: fmt.Sprintf(
@@ -619,7 +594,7 @@ func TestRateLimitKey_LongChainCapsWalkAndFallsBackToPeer(
 	start := time.Now()
 
 	assertSharedBucket(
-		t, trustedProxies(trustedProxyCIDR), trustedPeer,
+		t, trustedProxies("10.0.0.0/8"), "10.0.0.1:44444",
 		func(i int) map[string]string {
 			return map[string]string{
 				headerXFF: fmt.Sprintf("9.9.9.%d%s", i+1, padding),
@@ -658,13 +633,13 @@ func TestRateLimitKey_LongChainAllocationIsBounded(t *testing.T) {
 	)
 
 	m := rateLimitMiddleware(t, &config.Config{
-		TrustedProxies: trustedProxies(trustedProxyCIDR),
+		TrustedProxies: trustedProxies("10.0.0.0/8"),
 	})
 
 	req := httptest.NewRequestWithContext(
 		context.Background(), http.MethodPost, loginPath, nil,
 	)
-	req.RemoteAddr = trustedPeer
+	req.RemoteAddr = "10.0.0.1:44444"
 	req.Header.Set(
 		headerXFF, "9.9.9.9"+strings.Repeat(", 10.0.0.2", hops),
 	)
@@ -860,369 +835,3 @@ func TestReceiverRateLimit_IgnoresForwardedFromUntrustedPeer(
 			"not mint a fresh receiver bucket",
 	)
 }
-
-// clientKeyFor returns the bucket key m computes for a request whose
-// direct peer is remoteAddr and which carries no forwarded headers.
-func clientKeyFor(
-	t *testing.T, m *middleware.Middleware, remoteAddr string,
-) string {
-	t.Helper()
-
-	req := httptest.NewRequestWithContext(
-		context.Background(), http.MethodPost, loginPath, nil,
-	)
-	req.RemoteAddr = remoteAddr
-
-	return middleware.ClientKeyForTest(m, req)
-}
-
-// TestRateLimitKey_IPv6BucketsByPrefix pins the key function's
-// address-family behaviour. IPv6 clients must bucket by /64 — a
-// routed /64 is the normal residential and mobile allocation, so
-// per-/128 keying lets one subscriber rotate source addresses and
-// mint a fresh bucket per request — while IPv4 keeps keying on the
-// full address and IPv4-mapped form is keyed as the IPv4 address it
-// carries.
-func TestRateLimitKey_IPv6BucketsByPrefix(t *testing.T) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{})
-
-	for _, tc := range []struct {
-		name  string
-		peer  string
-		want  string
-		about string
-	}{{
-		name:  "ipv6",
-		peer:  "[" + clientIPv6 + "]:44444",
-		want:  clientBucketV6,
-		about: "an IPv6 peer must key on its /64",
-	}, {
-		name:  "ipv6-other-in-same-64",
-		peer:  "[" + clientIPv6Same + "]:1",
-		want:  clientBucketV6,
-		about: "another address in the same /64 must key the same",
-	}, {
-		name:  "ipv6-different-64",
-		peer:  "[" + clientIPv6Other + "]:44444",
-		want:  clientOtherBucketV6,
-		about: "a different /64 must key differently",
-	}, {
-		name:  "ipv4",
-		peer:  clientIPv4 + ":44444",
-		want:  clientIPv4,
-		about: "IPv4 must keep keying on the full address",
-	}, {
-		name:  "ipv4-neighbour",
-		peer:  clientIPv4Alt + ":44444",
-		want:  clientIPv4Alt,
-		about: "adjacent IPv4 addresses must not share a bucket",
-	}, {
-		name: "ipv4-mapped",
-		peer: "[::ffff:" + clientIPv4 + "]:44444",
-		want: clientIPv4,
-		about: "IPv4-mapped form must key as the IPv4 address, " +
-			"not be masked to a /64: mapped addresses all share " +
-			"::ffff:0:0/96, so masking would collapse every IPv4 " +
-			"client behind a mapping proxy into one bucket",
-	}} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			assert.Equal(
-				t, tc.want, clientKeyFor(t, m, tc.peer), tc.about,
-			)
-		})
-	}
-}
-
-// TestRateLimitKey_FamiliesDoNotCollide pins the structure the
-// no-collision property rests on, rather than one sample pair: every
-// IPv4 key is a bare address and every IPv6 key is a /64 in CIDR
-// form, so the two name spaces are disjoint by shape. Dropping the
-// masking strips the suffix that guarantees it, which is why this
-// asserts the form of each key and not just that two of them differ.
-func TestRateLimitKey_FamiliesDoNotCollide(t *testing.T) {
-	t.Parallel()
-
-	// Restated here rather than imported from the package under
-	// test, so that changing the production bucket width fails this
-	// test instead of silently moving with it.
-	const wantBits = 64
-
-	m := rateLimitMiddleware(t, &config.Config{})
-
-	v4Keys := map[string]bool{}
-
-	for _, peer := range []string{
-		clientIPv4 + ":44444",
-		clientIPv4Alt + ":44444",
-		"[::ffff:" + clientIPv4 + "]:44444",
-	} {
-		key := clientKeyFor(t, m, peer)
-
-		addr, err := netip.ParseAddr(key)
-		require.NoError(
-			t, err, "%s: an IPv4 key must be a bare address", peer,
-		)
-		assert.True(
-			t, addr.Is4(),
-			"%s: an IPv4 key must be a dotted quad, got %q", peer, key,
-		)
-
-		v4Keys[key] = true
-	}
-
-	for _, peer := range []string{
-		"[" + clientIPv6 + "]:44444",
-		"[" + clientIPv6Same + "]:44444",
-		"[" + clientIPv6Other + "]:44444",
-		"[2001:db8::" + clientIPv4 + "]:44444",
-	} {
-		key := clientKeyFor(t, m, peer)
-
-		prefix, err := netip.ParsePrefix(key)
-		require.NoError(
-			t, err, "%s: an IPv6 key must be a CIDR prefix", peer,
-		)
-		assert.Equal(
-			t, wantBits, prefix.Bits(),
-			"%s: an IPv6 key must name a /64", peer,
-		)
-		assert.False(
-			t, v4Keys[key],
-			"%s: an IPv6 key must never equal an IPv4 key", peer,
-		)
-	}
-}
-
-// TestRateLimitKey_UnparseablePeerKeepsDistinctBuckets covers the
-// fallback path. A RemoteAddr that is not an address must not panic,
-// and must not drop unrelated clients into one shared bucket by
-// accident: the raw value is the most specific identity left, so
-// distinct values stay in distinct buckets.
-func TestRateLimitKey_UnparseablePeerKeepsDistinctBuckets(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{})
-
-	first := clientKeyFor(t, m, "not-an-address")
-	second := clientKeyFor(t, m, "also-not-an-address:1234")
-
-	assert.NotEmpty(t, first)
-	assert.NotEqual(
-		t, first, second,
-		"unparseable peers must not collapse into one bucket",
-	)
-}
-
-// TestLoginRateLimit_IPv6SharesBucketWithinSlash64 is the behavioural
-// half, and the regression test for the bypass itself: a client that
-// rotates source addresses inside its own routed /64 must stay in one
-// bucket. Reverting the masking makes this test fail, because each
-// rotated address would mint a fresh bucket and nothing would be
-// rejected.
-func TestLoginRateLimit_IPv6SharesBucketWithinSlash64(t *testing.T) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{})
-	handler := m.LoginRateLimit()(okHandler())
-
-	for i := range middleware.LoginRateLimitConst {
-		w := postWithHeaders(
-			handler,
-			fmt.Sprintf("[2001:db8:1:2::%d]:44444", i+1),
-			loginPath, nil,
-		)
-		assert.Equal(
-			t, http.StatusOK, w.Code, "request %d should pass", i,
-		)
-	}
-
-	w := postWithHeaders(
-		handler, "[2001:db8:1:2::ffff]:44444", loginPath, nil,
-	)
-	assert.Equal(
-		t, http.StatusTooManyRequests, w.Code,
-		"rotating source addresses inside one routed /64 must not "+
-			"mint fresh buckets",
-	)
-}
-
-// TestLoginRateLimit_IPv6IndependentAcrossSlash64 is the other side
-// of the trade: bucketing by /64 must not merge separate allocations,
-// so a client in a different /64 keeps its own limit.
-func TestLoginRateLimit_IPv6IndependentAcrossSlash64(t *testing.T) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{})
-	handler := m.LoginRateLimit()(okHandler())
-
-	for range middleware.LoginRateLimitConst + 1 {
-		postWithHeaders(
-			handler, "[2001:db8:1:2::1]:44444", loginPath, nil,
-		)
-	}
-
-	w := postWithHeaders(
-		handler, "[2001:db8:1:3::1]:44444", loginPath, nil,
-	)
-	assert.Equal(
-		t, http.StatusOK, w.Code,
-		"a different /64 must have its own bucket",
-	)
-}
-
-// TestLoginRateLimit_IPv4IndependentPerAddress guards against the
-// masking leaking into IPv4: two addresses one apart must still hold
-// separate buckets.
-func TestLoginRateLimit_IPv4IndependentPerAddress(t *testing.T) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{})
-	handler := m.LoginRateLimit()(okHandler())
-
-	for range middleware.LoginRateLimitConst + 1 {
-		postWithHeaders(
-			handler, clientIPv4+":44444", loginPath, nil,
-		)
-	}
-
-	w := postWithHeaders(
-		handler, clientIPv4Alt+":44444", loginPath, nil,
-	)
-	assert.Equal(
-		t, http.StatusOK, w.Code,
-		"a second IPv4 address must have its own bucket",
-	)
-}
-
-// forwardedKeyFor returns the bucket key m computes for a request
-// that arrives from trustedPeer — a configured trusted proxy — and
-// names forwarded as its client in X-Forwarded-For. That is the
-// production path: a deployment is required to run behind a reverse
-// proxy with TRUSTED_PROXIES set, so the forwarded address, not the
-// peer, is what the limiters bucket on there.
-func forwardedKeyFor(
-	t *testing.T, m *middleware.Middleware, forwarded string,
-) string {
-	t.Helper()
-
-	req := httptest.NewRequestWithContext(
-		context.Background(), http.MethodPost, loginPath, nil,
-	)
-	req.RemoteAddr = trustedPeer
-	req.Header.Set(headerXFF, forwarded)
-
-	return middleware.ClientKeyForTest(m, req)
-}
-
-// TestRateLimitKey_ForwardedIPv6BucketsByPrefix pins the /64
-// bucketing on the trusted-proxy branch. The direct-peer tests above
-// cannot reach it, so without this the masking could be reverted for
-// forwarded clients alone — the only shape a production deployment
-// runs in — and the rest of the suite would stay green.
-func TestRateLimitKey_ForwardedIPv6BucketsByPrefix(t *testing.T) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{
-		TrustedProxies: trustedProxies(trustedProxyCIDR),
-	})
-
-	for _, tc := range []struct {
-		name      string
-		forwarded string
-		want      string
-		about     string
-	}{{
-		name:      "ipv6",
-		forwarded: clientIPv6,
-		want:      clientBucketV6,
-		about:     "a forwarded IPv6 client must key on its /64",
-	}, {
-		name:      "ipv6-other-in-same-64",
-		forwarded: clientIPv6Same,
-		want:      clientBucketV6,
-		about: "another forwarded address in the same /64 must " +
-			"key the same",
-	}, {
-		name:      "ipv6-different-64",
-		forwarded: clientIPv6Other,
-		want:      clientOtherBucketV6,
-		about:     "a forwarded address in another /64 must differ",
-	}, {
-		name:      "ipv4",
-		forwarded: clientIPv4,
-		want:      clientIPv4,
-		about:     "a forwarded IPv4 client must key on the address",
-	}, {
-		name:      "ipv4-mapped",
-		forwarded: "::ffff:" + clientIPv4,
-		want:      clientIPv4,
-		about: "a proxy that forwards IPv4-mapped form must key as " +
-			"the IPv4 address it carries, not be masked to a /64: " +
-			"mapped addresses all share ::ffff:0:0/96",
-	}} {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			assert.Equal(
-				t, tc.want,
-				forwardedKeyFor(t, m, tc.forwarded), tc.about,
-			)
-		})
-	}
-}
-
-// TestLoginRateLimit_ForwardedIPv6SharesBucketWithinSlash64 is the
-// behavioural half on the production path: behind a trusted proxy, a
-// client rotating source addresses inside its own routed /64 must
-// stay in one bucket.
-func TestLoginRateLimit_ForwardedIPv6SharesBucketWithinSlash64(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	assertSharedBucket(
-		t, trustedProxies(trustedProxyCIDR), trustedPeer,
-		func(i int) map[string]string {
-			return map[string]string{
-				headerXFF: fmt.Sprintf("2001:db8:1:2::%d", i+1),
-			}
-		},
-		"rotating forwarded source addresses inside one routed /64 "+
-			"must not mint fresh buckets",
-	)
-}
-
-// TestLoginRateLimit_ForwardedIPv6IndependentAcrossSlash64 is the
-// other side of that trade on the same path: bucketing by /64 must
-// not merge two allocations reaching the proxy.
-func TestLoginRateLimit_ForwardedIPv6IndependentAcrossSlash64(
-	t *testing.T,
-) {
-	t.Parallel()
-
-	m := rateLimitMiddleware(t, &config.Config{
-		TrustedProxies: trustedProxies(trustedProxyCIDR),
-	})
-	handler := m.LoginRateLimit()(okHandler())
-
-	spent := map[string]string{headerXFF: clientIPv6}
-	for range middleware.LoginRateLimitConst + 1 {
-		postWithHeaders(handler, trustedPeer, loginPath, spent)
-	}
-
-	w := postWithHeaders(
-		handler, trustedPeer, loginPath,
-		map[string]string{headerXFF: clientIPv6Other},
-	)
-	assert.Equal(
-		t, http.StatusOK, w.Code,
-		"a forwarded client in a different /64 must have its own "+
-			"bucket",
-	)
-}