kittens: Dont discard pending input on startup

Fixes #3012

kittens/tui/loop.py

@@ -10,6 +10,7 @@ import re
 import selectors
 import signal
 import sys
+import termios
 from contextlib import contextmanager
 from functools import partial
 from typing import Any, Callable, Dict, Generator, List, NamedTuple, Optional
@@ -61,8 +62,9 @@ debug = Debug()
 
 class TermManager:
 
-    def __init__(self) -> None:
+    def __init__(self, optional_actions: int = termios.TCSANOW) -> None:
         self.extra_finalize: Optional[str] = None
+        self.optional_actions = optional_actions
 
     def set_state_for_loop(self, set_raw: bool = True) -> None:
         if set_raw:
@@ -82,7 +84,7 @@ class TermManager:
         self.set_state_for_loop()
 
     def __enter__(self) -> 'TermManager':
-        self.tty_fd, self.original_termios = open_tty()
+        self.tty_fd, self.original_termios = open_tty(False, self.optional_actions)
         self.set_state_for_loop(set_raw=False)
         return self
 
@@ -183,7 +185,8 @@ class Loop:
 
     def __init__(
         self,
-        sanitize_bracketed_paste: str = '[\x03\x04\x0e\x0f\r\x07\x7f\x8d\x8e\x8f\x90\x9b\x9d\x9e\x9f]'
+        sanitize_bracketed_paste: str = '[\x03\x04\x0e\x0f\r\x07\x7f\x8d\x8e\x8f\x90\x9b\x9d\x9e\x9f]',
+        optional_actions: int = termios.TCSADRAIN
     ):
         if is_macos:
             # On macOS PTY devices are not supported by the KqueueSelector and
@@ -193,6 +196,7 @@ class Loop:
         else:
             self.asycio_loop = asyncio.get_event_loop()
         self.return_code = 0
+        self.optional_actions = optional_actions
         self.read_buf = ''
         self.decoder = codecs.getincrementaldecoder('utf-8')('ignore')
         try:
@@ -388,7 +392,7 @@ class Loop:
             handler.on_resize(handler.screen_size)
 
         signal_manager = SignalManager(self.asycio_loop, _on_sigwinch, handler.on_interrupt, handler.on_term)
-        with TermManager() as term_manager, signal_manager:
+        with TermManager(self.optional_actions) as term_manager, signal_manager:
             self._get_screen_size: ScreenSizeGetter = screen_size_function(term_manager.tty_fd)
             image_manager = None
             if handler.image_manager_class is not None:

kitty/data-types.c

@@ -105,8 +105,8 @@ put_tty_in_raw_mode(int fd, const struct termios* termios_p, bool read_with_time
 
 static PyObject*
 open_tty(PyObject *self UNUSED, PyObject *args) {
-    int read_with_timeout = 0;
+    int read_with_timeout = 0, optional_actions = TCSAFLUSH;
-    if (!PyArg_ParseTuple(args, "|p", &read_with_timeout)) return NULL;
+    if (!PyArg_ParseTuple(args, "|pi", &read_with_timeout, &optional_actions)) return NULL;
     int flags = O_RDWR | O_CLOEXEC | O_NOCTTY;
     if (!read_with_timeout) flags |= O_NONBLOCK;
     static char ctty[L_ctermid+1];
@@ -115,13 +115,13 @@ open_tty(PyObject *self UNUSED, PyObject *args) {
     struct termios *termios_p = calloc(1, sizeof(struct termios));
     if (!termios_p) return PyErr_NoMemory();
     if (tcgetattr(fd, termios_p) != 0) { free(termios_p); PyErr_SetFromErrno(PyExc_OSError); return NULL; }
-    if (!put_tty_in_raw_mode(fd, termios_p, read_with_timeout != 0, TCSAFLUSH)) { free(termios_p); return NULL; }
+    if (!put_tty_in_raw_mode(fd, termios_p, read_with_timeout != 0, optional_actions)) { free(termios_p); return NULL; }
     return Py_BuildValue("iN", fd, PyLong_FromVoidPtr(termios_p));
 }
 
 #define TTY_ARGS \
     PyObject *tp; int fd; int optional_actions = TCSAFLUSH; \
-    if (!PyArg_ParseTuple(args, "iO!|", &fd, &PyLong_Type, &tp, &optional_actions)) return NULL; \
+    if (!PyArg_ParseTuple(args, "iO!|i", &fd, &PyLong_Type, &tp, &optional_actions)) return NULL; \
     struct termios *termios_p = PyLong_AsVoidPtr(tp);
 
 static PyObject*

kitty/fast_data_types.pyi

@@ -878,7 +878,7 @@ def normal_tty(fd: int, termios_ptr: TermiosPtr, optional_actions: int = termios
     pass
 
 
-def open_tty(read_with_timeout: bool = False) -> Tuple[int, TermiosPtr]:
+def open_tty(read_with_timeout: bool = False, optional_actions: int = termios.TCSAFLUSH) -> Tuple[int, TermiosPtr]:
     pass