Get rid of kitty's special OSC 52 protocol

A better solution from an ecosystem perspective is to just work with the
original protocol. I have modified kitty's escape parser to special case
OSC 52 handling without changing its max escape code size.

Basically, it works by splitting up OSC 52 escape codes longer than the
max size into a series of partial OSC 52 escape codes. These get
dispatched to the UI layer where it accumulates them upto the 8MB limit
and then sends to clipboard when the partial sequence ends.

See https://github.com/ranger/ranger/issues/1861

kitty/window.py

@@ -12,8 +12,8 @@ from functools import partial
 from gettext import gettext as _
 from itertools import chain
 from typing import (
-    Any, Callable, Deque, Dict, Iterable, List, Optional, Pattern, Sequence,
-    Tuple, Union
+    Any, Callable, Deque, Dict, Iterable, List, NamedTuple, Optional, Pattern,
+    Sequence, Tuple, Union
 )
 
 from .child import ProcessDesc
@@ -72,6 +72,11 @@ class PipeData(TypedDict):
     text: str
 
 
+class ClipboardPending(NamedTuple):
+    where: str
+    data: str
+
+
 class DynamicColor(IntEnum):
     default_fg, default_bg, cursor_color, highlight_fg, highlight_bg = range(1, 6)
 
@@ -337,7 +342,7 @@ class Window:
         self.tab_id = tab.id
         self.os_window_id = tab.os_window_id
         self.tabref: Callable[[], Optional[TabType]] = weakref.ref(tab)
-        self.clipboard_control_buffers = {'p': '', 'c': ''}
+        self.clipboard_pending: Optional[ClipboardPending] = None
         self.destroyed = False
         self.geometry: WindowGeometry = WindowGeometry(0, 0, 0, 0, 0, 0)
         self.needs_layout = True
@@ -777,10 +782,25 @@ class Window:
     def send_cmd_response(self, response: Any) -> None:
         self.screen.send_escape_code_to_child(DCS, '@kitty-cmd' + json.dumps(response))
 
-    def clipboard_control(self, data: str) -> None:
+    def clipboard_control(self, data: str, is_partial: bool = False) -> None:
         where, text = data.partition(';')[::2]
+        if is_partial:
+            if self.clipboard_pending is None:
+                self.clipboard_pending = ClipboardPending(where, text)
+            else:
+                self.clipboard_pending = self.clipboard_pending._replace(data=self.clipboard_pending[1] + text)
+                if len(self.clipboard_pending.data) > 8 * 1024 * 1024:
+                    log_error('Discarding part of too large OSC 52 paste request')
+                    self.clipboard_pending = self.clipboard_pending._replace(data='')
+            return
+
         if not where:
-            where = 's0'
+            if self.clipboard_pending is not None:
+                text = self.clipboard_pending.data + text
+                where = self.clipboard_pending.where
+                self.clipboard_pending = None
+            else:
+                where = 's0'
         cc = get_options().clipboard_control
         if text == '?':
             response = None
@@ -802,22 +822,13 @@ class Window:
             except Exception:
                 text = ''
 
-            def write(key: str, func: Callable[[str], None]) -> None:
-                if text:
-                    if ('no-append' in cc or
-                            len(self.clipboard_control_buffers[key]) > 1024*1024):
-                        self.clipboard_control_buffers[key] = ''
-                    self.clipboard_control_buffers[key] += text
-                else:
-                    self.clipboard_control_buffers[key] = ''
-                func(self.clipboard_control_buffers[key])
-
             if 's' in where or 'c' in where:
                 if 'write-clipboard' in cc:
-                    write('c', set_clipboard_string)
+                    set_clipboard_string(text)
             if 'p' in where:
                 if 'write-primary' in cc:
-                    write('p', set_primary_selection)
+                    set_primary_selection(text)
+        self.clipboard_pending = None
 
     def manipulate_title_stack(self, pop: bool, title: str, icon: Any) -> None:
         if title: