httpcaddyfile: allocate route groups across named and site routes

Share the adaptation group counter with named-route extraction because group satisfaction is request-wide. Cover nested invoke and handle_path while retaining sibling exclusivity.

Addresses scan report fb62a11d-5561-49e3-87df-c175ea5a1f4d.

Code written by GitHub Copilot (GPT-6.1 Sol, Claude Opus 5.5); reviewed by mholt.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

caddyconfig/httpcaddyfile/httptype.go

@@ -104,7 +104,7 @@ func (st ServerType) Setup(
 	// with actual identifiers used by Caddy
 	replacer := NewShorthandReplacer()
 
-	originalServerBlocks, err = st.extractNamedRoutes(originalServerBlocks, options, &warnings, replacer)
+	originalServerBlocks, err = st.extractNamedRoutes(originalServerBlocks, options, &warnings, replacer, gc)
 	if err != nil {
 		return nil, warnings, err
 	}
@@ -477,11 +477,11 @@ func (ServerType) extractNamedRoutes(
 	options map[string]any,
 	warnings *[]caddyconfig.Warning,
 	replacer ShorthandReplacer,
+	gc counter,
 ) ([]serverBlock, error) {
 	namedRoutes := map[string]*caddyhttp.Route{}
 	namedRouteInvokes := map[string][]string{}
 
-	gc := counter{new(int)}
 	state := make(map[string]any)
 
 	// copy the server blocks so we can

caddyconfig/httpcaddyfile/named_groups_test.go

@@ -0,0 +1,98 @@
+package httpcaddyfile_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/caddyserver/caddy/v2"
+	"github.com/caddyserver/caddy/v2/modules/caddyhttp"
+	_ "github.com/caddyserver/caddy/v2/modules/caddyhttp/rewrite"
+)
+
+func TestNamedRouteGroupsAreDistinct(t *testing.T) {
+	for _, tc := range []struct {
+		name, named, site string
+	}{
+		{
+			name: "handle",
+			named: `&(guard) {
+	handle /api/admin {
+		respond "denied" 403
+	}
+	handle {
+		respond "public"
+	}
+}`,
+			site: `handle /api/* {
+	invoke guard
+	respond "allowed"
+}`,
+		},
+		{
+			name: "handle_path",
+			named: `&(guard) {
+	handle /admin {
+		respond "denied" 403
+	}
+	handle {
+		respond "public"
+	}
+}`,
+			site: `handle_path /api/* {
+	invoke guard
+	respond "allowed"
+}`,
+		},
+		{
+			name: "nested invoke",
+			named: `&(inner) {
+	handle /api/admin {
+		respond "denied" 403
+	}
+	handle {
+		respond "public"
+	}
+}
+&(guard) {
+	handle /api/* {
+		invoke inner
+	}
+	handle {
+		respond "outer"
+	}
+}`,
+			site: `handle /api/* {
+	invoke guard
+	respond "allowed"
+}`,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			server, handler := adaptedRouteHandler(t, "{\nadmin off\nauto_https off\n}\n"+tc.named+"\n:9080 {\n"+tc.site+`
+	handle {
+		respond "fallback" 404
+	}
+}`)
+			for _, request := range []struct {
+				path string
+				code int
+				body string
+			}{
+				{"/api/admin", http.StatusForbidden, "denied"},
+				{"/api/public", http.StatusOK, "public"},
+				{"/other", http.StatusNotFound, "fallback"},
+			} {
+				req := httptest.NewRequest(http.MethodGet, request.path, nil)
+				req = caddyhttp.PrepareRequest(req, caddy.NewReplacer(), nil, server)
+				rec := httptest.NewRecorder()
+				if err := handler.ServeHTTP(rec, req); err != nil {
+					t.Fatal(err)
+				}
+				if rec.Code != request.code || rec.Body.String() != request.body {
+					t.Errorf("%s: got %d %q, want %d %q", request.path, rec.Code, rec.Body.String(), request.code, request.body)
+				}
+			}
+		})
+	}
+}