hl-DiffChange should be overwritten by matchadd() ?

[mattn]

Hi list.

http://ftp.vim.org/vim/patches/7.4/7.4.682

This fixes bug of cursorline. After 7.4.682, Behavior of highlighting of line are changed.

a.txt
-----------------------
aaa xxx aaa xxx aaa
-----------------------
b.txt
-----------------------
aaa yyy aaa yyy aaa
-----------------------

$ vim b.txt
:diffsplit a.txt
:call matchadd('MatchParen', 'aaa')

You can see:
https://cloud.githubusercontent.com/assets/3096934/7513011/f94c9b02-f4eb-11e4-8820-bf020da9ed66.png

Before 7.4.682, this was:
https://cloud.githubusercontent.com/assets/3096934/7512982/c42a2c82-f4eb-11e4-91f9-577087c24397.png

After 7.4.682, middle "aaa" remains bold highlight of DiffChange.

:hi DiffChange
DiffChange xxx term=bold ctermbg=5 guibg=DarkMagenta
:hi MatchParen
MatchParen xxx term=reverse ctermbg=3 guibg=DarkCyan

Vim handle hl-DiffChange/hl-CursorLine both as highlighting par-line. So 7.4.682 is applied to hl-DiffChange. I want to ask you that this is a bug or not. If you think this is a bug, 7.4.682 should be applied only for cursorline. If not, this behavior is right.

How do you think?

- mattn

[mattn]

Below is using diffchar.vim (http://www.vim.org/scripts/script.php?script_id=4932)

Before 7.4.682
https://cloud.githubusercontent.com/assets/3096934/7533396/09fc0828-f5ac-11e4-9023-823dbf4debd9.png

After 7.4.682
https://cloud.githubusercontent.com/assets/3096934/7533399/0eb543a2-f5ac-11e4-8ce8-28e4826998d4.png

- mattn