[patch] Wrong visual and 'cuc' highlighting in diff mode

[Lech Lorens]

The attached patch fixes the incorrect highlighting of the current column
(with 'cuc' set) and the visual blocks in changed/added lines in diff
mode. Such bad behaviour can be observed if the view of the diffed
buffer gets shifted to the right (e.g. with zl) so that the
changed/added line is shorter than the shift offset.

Examples of the described behaviour are depicted in the following screen
shots:
- visual block:
http://llorens.visualserver.org/wrong-cuc-highlight/visual-wrong.png
- current column:
http://llorens.visualserver.org/wrong-cuc-highlight/cuc-wrong.png

While the screen shots should show:
- visual block:
http://llorens.visualserver.org/wrong-cuc-highlight/visual-ok.png
- current column:
http://llorens.visualserver.org/wrong-cuc-highlight/cuc-ok.png

To reproduce the problem invoke vim with the following command line
arguments:
- visual block:
$ vim -u NONE -c 'normal iabcdefghijklmnopqrstuvwxyz' \
-c 'normal yyp' \
-c 'belowright vert new | normal 2pggddp' \
-c 'windo diffthis | normal gg9|5zl 2j2l'

- current column:
$ vim -u NONE -c 'normal iabcdefghijklmnopqrstuvwxyz' \
-c 'normal yyp' \
-c 'belowright vert new | normal 2pggddp' \
-c 'windo diffthis | normal gg9|5zl' \
-c 'set cuc'

--
Cheers,
Lech

[Bram Moolenaar]

Lech Lorens wrote:

Thanks!

--
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