fix error when exiting inline more prematurely

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Fixed
+
+- Fixed crash when exiting the app prematurely https://github.com/Textualize/textual/pull/5039
+
 ## [0.80.0] - 2024-09-23
 
 ### Added

src/textual/drivers/linux_driver.py

@@ -408,6 +408,7 @@ def process_selector_events(
         try:
             while not self.exit_event.is_set():
                 process_selector_events(selector.select(0.1))
+            selector.unregister(self.fileno)
             process_selector_events(selector.select(0.1), final=True)
 
         finally:

src/textual/drivers/linux_inline_driver.py

@@ -161,11 +161,11 @@ def process_selector_events(
                     self.cursor_origin = (event.x, event.y)
                 else:
                     self.process_event(event)
-                self.process_event(event)
 
         try:
             while not self.exit_event.is_set():
                 process_selector_events(selector.select(0.1))
+            selector.unregister(self.fileno)
             process_selector_events(selector.select(0.1), final=True)
 
         finally:
@@ -296,7 +296,10 @@ def disable_input(self) -> None:
                 if self._key_thread is not None:
                     self._key_thread.join()
                 self.exit_event.clear()
-                termios.tcflush(self.fileno, termios.TCIFLUSH)
+                try:
+                    termios.tcflush(self.fileno, termios.TCIFLUSH)
+                except termios.error:
+                    pass
 
         except Exception as error:
             # TODO: log this

src/textual/screen.py

@@ -451,7 +451,7 @@ def render(self) -> RenderableType:
         background = self.styles.background
         try:
             base_screen = visible_screen_stack.get().pop()
-        except IndexError:
+        except LookupError:
             base_screen = None
 
         if base_screen is not None and background.a < 1:

src/textual/widgets/_directory_tree.py

@@ -35,6 +35,7 @@ class DirectoryTree(Tree[DirEntry]):
     ICON_NODE_EXPANDED = "📂 "
     ICON_NODE = "📁 "
     ICON_FILE = "📄 "
+    """Unicode 'icon' to represent a file."""
 
     COMPONENT_CLASSES: ClassVar[set[str]] = {
         "directory-tree--extension",

src/textual/widgets/_tree.py

@@ -517,7 +517,9 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
     """A widget for displaying and navigating data in a tree."""
 
     ICON_NODE = "▶ "
+    """Unicode 'icon' to use for an expandable node."""
     ICON_NODE_EXPANDED = "▼ "
+    """Unicode 'icon' to use for an expanded node."""
 
     BINDINGS: ClassVar[list[BindingType]] = [
         Binding("shift+left", "cursor_parent", "Cursor to parent", show=False),

tests/test_app.py

@@ -3,7 +3,7 @@
 from rich.terminal_theme import DIMMED_MONOKAI, MONOKAI, NIGHT_OWLISH
 
 from textual.app import App, ComposeResult
-from textual.widgets import Button, Input
+from textual.widgets import Button, Input, Static
 
 
 def test_batch_update():
@@ -140,3 +140,36 @@ async def test_ansi_theme():
 
         app.dark = True
         assert app.ansi_theme == DIMMED_MONOKAI
+
+
+async def test_early_exit():
+    """Test exiting early doesn't cause issues."""
+    from textual.app import App
+
+    class AppExit(App):
+        def compose(self):
+            yield Static("Hello")
+
+        def on_mount(self) -> None:
+            # Exit after creating app
+            self.exit()
+
+    app = AppExit()
+    async with app.run_test():
+        pass
+
+
+def test_early_exit_inline():
+    """Test exiting early in inline mode doesn't break."""
+    from textual.app import App
+
+    class AppExit(App):
+        def compose(self):
+            yield Static("Hello")
+
+        def on_mount(self) -> None:
+            # Exit after creating app
+            self.exit()
+
+    app = AppExit()
+    app.run(inline=True, inline_no_clear=True)