bug#30281: list-matching-lines-jump-to-current-line inserts duplicate line

[Juri Linkov]

>> 0. emacs -Q
>> 1. Eval: (setq list-matching-lines-jump-to-current-line t)
>> 2. M-<
>> 3. M-s o text RET
>>
>> Two identical lines are displayed in *Occur*.
>>
>> As a possible solution, when the current line contains matches
>> I propose to use add-text-properties to add the face from
>> list-matching-lines-current-line-face over the matched current line.
>
> Sorry, I meant add-face-text-property to add background from
> list-matching-lines-current-line-face, while still keeping
> highlighting of match faces over matches on the current line
> in *Occur*.

What is worse it's completely broken for context lines.

For example, with the buffer

a
b
c
z
a
b
c
z
a
b
c

go to the line with the second occurrence of "z" and type
C-u 1 M-s o z RET

The result:

2 matches for "z" in buffer: *scratch*
       :c
      4:z
      8:z
       :a
-------
       :c
      8:z
       :a

Now this is fixed in master.