diff --git a/src/app/command_driver/utilities.rs b/src/app/command_driver/utilities.rs
index 05759388d..07c78f99e 100644
--- a/src/app/command_driver/utilities.rs
+++ b/src/app/command_driver/utilities.rs
@@ -1177,7 +1177,13 @@ impl OpenCADStudio {
 
         // 2. Blank line submits Enter to the active command (or repeats last).
         if trimmed.is_empty() {
-            return self.feed_command(StepInput::Enter);
+            if self.tabs[i].active_cmd.is_some() {
+                return self.feed_command(StepInput::Enter);
+            }
+            if let Some(cmd) = self.tabs[i].last_cmd.clone() {
+                return self.run_command_line(&cmd);
+            }
+            return Task::none();
         }
 
         // 3. A command is currently active: route to its prompt handlers.
diff --git a/src/app/commands/fileops.rs b/src/app/commands/fileops.rs
index ffe41dcfa..b5f69b303 100644
--- a/src/app/commands/fileops.rs
+++ b/src/app/commands/fileops.rs
@@ -552,4 +552,44 @@ ZOOM EXTENTS
         // 4 square edges + 2 diagonal lines + 2 circles = 8 entities
         assert_eq!(app.tabs[i].scene.document.entities().count(), 8);
     }
+
+    #[test]
+    fn blank_line_repeats_last_command_when_idle() {
+        let mut app = fresh_app();
+        let i = app.active_tab;
+
+        // Blank line before any command does nothing and does not panic
+        let _ = app.update(Message::ScriptLine("".into()));
+        assert!(app.tabs[i].active_cmd.is_none());
+
+        // 1. Draw a line
+        let _ = app.update(Message::ScriptLine("LINE".into()));
+        let _ = app.update(Message::ScriptLine("0,0".into()));
+        let _ = app.update(Message::ScriptLine("10,10".into()));
+        let _ = app.update(Message::ScriptLine("".into())); // finishes LINE
+        assert_eq!(app.tabs[i].scene.document.entities().count(), 1);
+        assert!(app.tabs[i].active_cmd.is_none());
+
+        // 2. Blank line when idle repeats LINE
+        let _ = app.update(Message::ScriptLine("".into()));
+        assert!(app.tabs[i].active_cmd.is_some(), "Blank line should repeat LINE");
+        let _ = app.update(Message::ScriptLine("20,20".into()));
+        let _ = app.update(Message::ScriptLine("30,30".into()));
+        let _ = app.update(Message::ScriptLine("".into())); // finishes second LINE
+        assert_eq!(app.tabs[i].scene.document.entities().count(), 2);
+        assert!(app.tabs[i].active_cmd.is_none());
+
+        // 3. Single-line command repeat
+        let _ = app.update(Message::ScriptLine("CIRCLE 5,5 2".into()));
+        assert_eq!(app.tabs[i].scene.document.entities().count(), 3);
+        assert!(app.tabs[i].active_cmd.is_none());
+
+        // Blank line repeats CIRCLE
+        let _ = app.update(Message::ScriptLine("".into()));
+        assert!(app.tabs[i].active_cmd.is_some(), "Blank line should repeat CIRCLE");
+        let _ = app.update(Message::ScriptLine("15,15".into()));
+        let _ = app.update(Message::ScriptLine("3".into()));
+        assert_eq!(app.tabs[i].scene.document.entities().count(), 4);
+        assert!(app.tabs[i].active_cmd.is_none());
+    }
 }