Locate symbol endpoints with deeper paths (#249)

* Locate symbol endpoints with deeper paths

* Remove unnecessarily named return value

* Add test for deeper symbol path

internal/symbolz/symbolz.go

@@ -66,16 +66,13 @@ func Symbolize(p *profile.Profile, force bool, sources plugin.MappingSources, sy
 // symbolz returns the corresponding symbolz source for a profile URL.
 func symbolz(source string) string {
 	if url, err := url.Parse(source); err == nil && url.Host != "" {
-		if strings.Contains(url.Path, "/") {
-			if dir := path.Dir(url.Path); dir == "/debug/pprof" {
-				// For Go language profile handlers in net/http/pprof package.
-				url.Path = "/debug/pprof/symbol"
-			} else {
-				url.Path = "/symbolz"
-			}
-			url.RawQuery = ""
-			return url.String()
+		if strings.Contains(url.Path, "/debug/pprof/") {
+			url.Path = path.Clean(url.Path + "/../symbol")
+		} else {
+			url.Path = "/symbolz"
 		}
+		url.RawQuery = ""
+		return url.String()
 	}
 
 	return ""

internal/symbolz/symbolz_test.go

@@ -26,13 +26,14 @@ import (
 
 func TestSymbolzURL(t *testing.T) {
 	for try, want := range map[string]string{
-		"http://host:8000/profilez":                        "http://host:8000/symbolz",
-		"http://host:8000/profilez?seconds=5":              "http://host:8000/symbolz",
-		"http://host:8000/profilez?seconds=5&format=proto": "http://host:8000/symbolz",
-		"http://host:8000/heapz?format=legacy":             "http://host:8000/symbolz",
-		"http://host:8000/debug/pprof/profile":             "http://host:8000/debug/pprof/symbol",
-		"http://host:8000/debug/pprof/profile?seconds=10":  "http://host:8000/debug/pprof/symbol",
-		"http://host:8000/debug/pprof/heap":                "http://host:8000/debug/pprof/symbol",
+		"http://host:8000/profilez":                                               "http://host:8000/symbolz",
+		"http://host:8000/profilez?seconds=5":                                     "http://host:8000/symbolz",
+		"http://host:8000/profilez?seconds=5&format=proto":                        "http://host:8000/symbolz",
+		"http://host:8000/heapz?format=legacy":                                    "http://host:8000/symbolz",
+		"http://host:8000/debug/pprof/profile":                                    "http://host:8000/debug/pprof/symbol",
+		"http://host:8000/debug/pprof/profile?seconds=10":                         "http://host:8000/debug/pprof/symbol",
+		"http://host:8000/debug/pprof/heap":                                       "http://host:8000/debug/pprof/symbol",
+		"http://some.host:8080/some/deeper/path/debug/pprof/endpoint?param=value": "http://some.host:8080/some/deeper/path/debug/pprof/symbol",
 	} {
 		if got := symbolz(try); got != want {
 			t.Errorf(`symbolz(%s)=%s, want "%s"`, try, got, want)