Subject: Re: bug#66167: 29.1; wrap-prefix text property with :align-to space keyword broken

From: "Paul W. Rankin" <[email-masked]>
Date: Sat, 23 Sep 2023 19:24:25 +1000

On 2023-09-23 18:41, Eli Zaretskii wrote:
> tags 66167 notabug wontfix
> thanks
> 
>> Date: Sat, 23 Sep 2023 18:04:27 +1000
>> From:  "Paul W. Rankin" via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <[email-masked]>
>> 
>> Description:
>> 
>> The wrap-prefix text property with :align-to space keyword has been
>> broken. (Regression).
>> 
>> To reproduce:
>> 
>> 1. emacs -Q
>> 2. in *scratch*, ensure visual-line-mode is enabled
>> 3. insert enough text to wrap lines
>> 4. M-: (put-text-property (point-min) (point-max) 'wrap-prefix '(space
>> :align-to 10))
>> 
>> Expected results:
>> 
>> Wrapped text should align to column 10.
>> 
>> Actual result:
>> 
>> Wrapped text does not align. (No effect.)
> 
> This is not a bug.  The argument of :align-to specifies a column
> number, and the column number does not get reset when the line wraps
> or the window is hscrolled.  IOW, the column number is measured from
> the beginning of the physical line, not from the beginning of the
> screen line.
> 
> The previous code handled this incorrectly and inconsistently, and was
> fixed in Emacs 29 (or was it 28?).

You're suggesting that the wrap-prefix should not be applied to wrapped 
lines..??