fix clicking on border in line api

Author: willmcgugan

CHANGELOG.md

@@ -10,15 +10,14 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Fixed
 
 - Static and Label now accept Content objects, satisfying type checkers https://github.com/Textualize/textual/pull/5618
+- Fixed click selection not being disabled when allow_select was set to false https://github.com/Textualize/textual/issues/5627
+- Fixed crash on clicking line API border 
+
 
 ### Added
 
 - Added Widget.preflight_checks to perform some debug checks after a widget is instantiated, to catch common errors. https://github.com/Textualize/textual/pull/5588
 
-### Fixed
-
-- Fixed click selection not being disabled when allow_select was set to false https://github.com/Textualize/textual/issues/5627
-
 ## [2.1.2] - 2025-02-26
 
 ### Fixed

src/textual/_compositor.py

@@ -900,6 +900,9 @@ def get_widget_and_offset_at(
         x -= region.x + gutter_left
         y -= region.y + gutter_right
 
+        if y < 0:
+            return None, None
+
         visible_screen_stack.set(widget.app._background_screens)
         line = widget.render_line(y)
 

tests/test_widget.py

@@ -668,3 +668,16 @@ def compose(self) -> ComposeResult:
         assert labels[4].last_of_type
         assert labels[4].is_odd
         assert not labels[4].is_even
+
+
+async def test_click_line_api_border():
+    class MyApp(App):
+        def compose(self) -> ComposeResult:
+            self.my_log = Log()
+            self.my_log.styles.border = ("round", "white")
+            yield self.my_log
+
+    app = MyApp()
+    async with app.run_test() as pilot:
+        await pilot.pause()
+        await pilot.click("Log", (10, 0))