fix for render width

src/textual/render.py

@@ -2,13 +2,20 @@ from rich.console import Console, RenderableType
 from rich.protocol import rich_cast
 
 
-def measure(console: Console, renderable: RenderableType, default: int) -> int:
+def measure(
+    console: Console,
+    renderable: RenderableType,
+    default: int,
+    *,
+    container_width: int | None = None
+) -> int:
     """Measure a rich renderable.
 
     Args:
         console: A console object.
         renderable: Rich renderable.
         default: Default width to use if renderable does not expose dimensions.
+        container_width: Width of container or None to use console width.
 
     Returns:
         Width in cells
@@ -17,6 +24,13 @@ def measure(console: Console, renderable: RenderableType, default: int) -> int:
     renderable = rich_cast(renderable)
     get_console_width = getattr(renderable, "__rich_measure__", None)
     if get_console_width is not None:
-        render_width = get_console_width(console, console.options).maximum
+        render_width = get_console_width(
+            console,
+            (
+                console.options
+                if container_width is None
+                else console.options.update_width(container_width)
+            ),
+        ).maximum
         width = max(0, render_width)
     return width

src/textual/widget.py

@@ -795,7 +795,9 @@ class Widget(DOMNode):
         console = self.app.console
         renderable = self._render()
 
-        width = measure(console, renderable, container.width)
+        width = measure(
+            console, renderable, container.width, container_width=container.width
+        )
         if self.expand:
             width = max(container.width, width)
         if self.shrink:

tests/snapshot_tests/test_snapshots.py

@@ -193,3 +193,8 @@ def test_demo(snap_compare):
         press=["down", "down", "down", "_", "_", "_"],
         terminal_size=(100, 30),
     )
+
+
+def test_label_wrap(snap_compare):
+    """Test Label wrapping with a Panel"""
+    assert snap_compare("snapshot_apps/label_wrap.py")