Fix commandline --cursor-end (#11504)

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# Description
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In `commandline --cursor-end`, set `repl.cursor_pos` to the number of
bytes in the buffer, not the number of graphemes.

fixes: #11503

# User-Facing Changes
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crates/nu-cli/src/commands/commandline.rs

@@ -111,7 +111,7 @@ impl Command for Commandline {
         } else {
             let mut repl = engine_state.repl_state.lock().expect("repl state mutex");
             if call.has_flag(engine_state, stack, "cursor-end")? {
-                repl.cursor_pos = repl.buffer.graphemes(true).count();
+                repl.cursor_pos = repl.buffer.len();
                 Ok(Value::nothing(call.head).into_pipeline_data())
             } else if call.has_flag(engine_state, stack, "cursor")? {
                 let char_pos = repl

src/tests/test_commandline.rs

@@ -127,3 +127,11 @@ fn commandline_test_cursor_invalid() -> TestResult {
         r#"string "abc" does not represent a valid int"#,
     )
 }
+
+#[test]
+fn commandline_test_cursor_end() -> TestResult {
+    run_test(
+        "commandline --insert '🤔🤔'; commandline --cursor-end; commandline --cursor",
+        "2", // 2 graphemes
+    )
+}