Fix recursive macro crash and empty macro lockout (#2902)

helix-term/src/commands.rs

@@ -4655,8 +4655,6 @@ fn replay_macro(cx: &mut Context) {
         return;
     }
 
-    cx.editor.macro_replaying.push(reg);
-
     let keys: Vec<KeyEvent> = if let Some([keys_str]) = cx.editor.registers.read(reg) {
         match helix_view::input::parse_macro(keys_str) {
             Ok(keys) => keys,
@@ -4670,6 +4668,10 @@ fn replay_macro(cx: &mut Context) {
         return;
     };
 
+    // Once the macro has been fully validated, it's marked as being under replay
+    // to ensure we don't fall into infinite recursion.
+    cx.editor.macro_replaying.push(reg);
+
     let count = cx.count();
     cx.callback = Some(Box::new(move |compositor, cx| {
         for _ in 0..count {
@@ -4677,7 +4679,9 @@ fn replay_macro(cx: &mut Context) {
                 compositor.handle_event(crossterm::event::Event::Key(key.into()), cx);
             }
         }
-    }));
+        // The macro under replay is cleared at the end of the callback, not in the
-
+        // macro replay context, or it will not correctly protect the user from
+        // replaying recursively.
         cx.editor.macro_replaying.pop();
+    }));
 }