dig into actor url to verify id

activity.go

@@ -929,3 +929,27 @@ func gofish(name string) string {
 	handlock.Unlock()
 	return ""
 }
+
+func investigate(name string) string {
+	if name == "" {
+		return ""
+	}
+	if name[0] == '@' {
+		name = gofish(name)
+	}
+	if name == "" {
+		return ""
+	}
+	obj, err := GetJunk(name)
+	if err != nil {
+		log.Printf("error investigating honker: %s", err)
+		return ""
+	}
+	t, _ := jsongetstring(obj, "type")
+	id, _ := jsongetstring(obj, "id")
+	if t != "Person" {
+		log.Printf("it's not a person! %s", name)
+		return ""
+	}
+	return id
+}

docs/manual.txt

@@ -20,8 +20,7 @@ The easiest is probably their handle, the thing that resembles an email.
 @name@example.com for example.
 
 Alternatively, one may directly enter the actor ID, which is a URL that looks
-like https://example.com/users/name. Note that the commonly seen URL with
-@name in it is not their actor ID and won't work.
+like https://example.com/users/name.
 
 Followed honkers may be assigned to combos, listing all their honks together.
 

honk.go

@@ -1036,12 +1036,7 @@ func savehonker(w http.ResponseWriter, r *http.Request) {
 	if peep == "peep" {
 		flavor = "peep"
 	}
-	if url == "" {
-		return
-	}
-	if url[0] == '@' {
-		url = gofish(url)
-	}
+	url = investigate(url)
 	if url == "" {
 		return
 	}