HTML Test: textarea with dir=auto, script assigns to all-N between all-Rs

Test passes if the two boxes below look exactly the same.

Key to entities used below: א - The Hebrew letter Alef (strongly RTL). This test makes sure that the direction is set correctly for a textarea whose value is set dynamically by script. We use text-align:left because neither the dir="auto" nor the unicode-bidi:plaintext specification states whether text-align:start and text-align:end should obey the paragraph direction or the direction property in a unicode-bidi:plaintext element. The ...! paragraph, being neutral, is supposed to be displayed LTR (i.e. as ...!, not as !...) despite both the paragraph before it and the paragraph after it being all-RTL, which makes the element as a whole RTL.
LTR text
LTR text
א !... א
א !... א