core: layout: modify tab with fn to a literal tab character

src/core/layout.rs

@@ -186,6 +186,9 @@ impl Part {
     fn modify_fn(orig_sym: &KeyValue) -> KeyValue
     {
         match orig_sym {
+            KeyValue(Keysym::Tab, _)
+                => KeyValue::from(Keysym::NoSymbol, "\t"),
+
             KeyValue(Keysym::Up, _)
                 => KeyValue::from(Keysym::Prior, "⇑"), // Page Up
             KeyValue(Keysym::Down, _)
@@ -445,6 +448,7 @@ impl Part {
     {
         match self.val.1.as_ref() {
             " " => "␣",
+            "\t" => "\\t",
             l => l,
         }
     }