From fda018a324ee44606b96327e98c8da5e97940b0a Mon Sep 17 00:00:00 2001
From: Rufino Cabrera <rufino@aliasrobotics.com>
Date: Thu, 11 Jun 2026 10:25:45 +0200
Subject: [PATCH] Fix REPL y/N prompts showing ^M after Enter

Restore cooked TTY state after prompt_toolkit exits so Rich console.input
and other follow-up prompts (e.g. /compact confirmation) accept Enter normally.
---
 src/cai/repl/ui/prompt.py           | 10 ++++++++++
 tests/repl/test_multiline_prompt.py | 23 +++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/cai/repl/ui/prompt.py b/src/cai/repl/ui/prompt.py
index daf5f950..a3b351e6 100644
--- a/src/cai/repl/ui/prompt.py
+++ b/src/cai/repl/ui/prompt.py
@@ -216,6 +216,7 @@ def get_user_input(command_completer, key_bindings, history_file, toolbar_func,
         return [sep_line]
 
     # Get user input with all features
+    result = ""
     try:
         result = prompt(
             [("class:prompt", "CAI> ")],
@@ -244,6 +245,15 @@ def get_user_input(command_completer, key_bindings, history_file, toolbar_func,
         except (AttributeError, OSError):
             _REPL_STDIN_EXHAUSTED_PENDING = True
         return ""
+    finally:
+        # prompt_toolkit restores termios from the snapshot taken after we cleared
+        # ICRNL above; Rich console.input and plain input() then echo Enter as ^M.
+        try:
+            from cai.util.streaming import restore_terminal_state
+
+            restore_terminal_state(emit_trailing_newline=False)
+        except Exception:
+            pass
 
     # Print bottom separator only when user submitted non-empty input,
     # so that empty Enter produces a single separator between prompts.
diff --git a/tests/repl/test_multiline_prompt.py b/tests/repl/test_multiline_prompt.py
index e4938498..4835055b 100644
--- a/tests/repl/test_multiline_prompt.py
+++ b/tests/repl/test_multiline_prompt.py
@@ -33,6 +33,29 @@ class TestMultilinePromptConfig:
             'Without this, Enter may only insert newlines after long agent turns.'
         )
 
+    def test_tty_restored_after_prompt(self):
+        """Cooked TTY must be restored after prompt() for follow-up console.input prompts.
+
+        We clear ICRNL before prompt_toolkit starts; on exit it restores that snapshot,
+        so /compact and other y/N confirmations see Enter as ^M unless we run
+        restore_terminal_state again in a finally block.
+        """
+        from cai.repl.ui.prompt import get_user_input
+        import inspect
+
+        source = inspect.getsource(get_user_input)
+
+        assert 'finally:' in source, (
+            'REGRESSION: get_user_input must use finally to restore the TTY after '
+            'prompt_toolkit exits. Without this, Rich console.input shows ^M on Enter.'
+        )
+        assert source.index('finally:') > source.index('prompt('), (
+            'REGRESSION: TTY restore must run after prompt(), not only before it.'
+        )
+        assert 'restore_terminal_state' in source[source.index('finally:'):], (
+            'REGRESSION: finally block must call restore_terminal_state after prompt().'
+        )
+
     def test_icrnl_cleared_before_prompt(self):
         """ICRNL/INLCR/IGNCR must be cleared before prompt() to keep Enter as submit.