TextArea.placeholder renders incorrectly if it contains newline characters #6122
Description
I was trying to add a little bit of help text to a TextArea in Posting, as it's prime real estate for it :)
Example
from textual.app import App, ComposeResult
from textual.widgets import TextArea
class TextAreaPlaceholderMultipleLines(App[None]):
def compose(self) -> ComposeResult:
yield TextArea(placeholder="Line 1\nLine 2\nLine 3")
if __name__ == "__main__":
app = TextAreaPlaceholderMultipleLines()
app.run()Result
