fix darkmode toggle

routes.go

@@ -772,14 +772,14 @@ func Settings(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
 			setCookie(w, "", name, r.FormValue(name))
 		}
 		state.Dark = new(bool)
-		if r.FormValue("undarkmode") == "" {
+		dark := r.FormValue("darkmode")
+		undark := r.FormValue("undarkmode")
+		if dark == "0" && undark != "0" {
+		} else if dark == "0" && undark == "0" {
 			setCookie(w, "", "Dark", "0")
-		} else if r.FormValue("darkmode") != "" {
+		} else {
 			setCookie(w, "", "Dark", "1")
 			*state.Dark = true
-		} else {
-			setCookie(w, "", "Dark", "0")
-			*state.Dark = false
 		}
 		if r.FormValue("shownsfw") != "" {
 			setCookie(w, "", "ShowNSFW", "1")

templates/settings.html

@@ -111,12 +111,16 @@
           dark mode
         </label>
         <input type="checkbox" name="darkmode" {{ if is .Dark }}checked{{end}}>
+        <input type="hidden" name="darkmode" value="0">
       </div>
       <div id="undarkmode">
         <label>
           dark mode
         </label>
+          {{ if not .Dark }}
         <input type="checkbox" name="undarkmode" checked>
+          {{ end }}
+          <input type="hidden" name="undarkmode" value="0">
       </div>
       <div class="scripting">
         <label>