Compiling with ncurses instead of ncursesw breaks alignment/repaint

[mqudsi]

Compiling tig (from master) with libncurses-dev but no libncursesw5-dev installed causes tig to experience some alignment issues and repaint problems that do not happen with libncursesw5-dev installed/used instead.

Here's how it looks with the following configuration:

...
configure: WARNING: The found ncurses library does not support wide-char.
configure: WARNING: This means that tig will not correctly render UTF-8.
...

giving

tig version 2.5.7
ncursesw version 6.1.20180127 # this is wrong?
readline version 7.0
PCRE2 version 10.31 2018-02-12

https://user-images.githubusercontent.com/606923/197015041-bfb6fbbd-8ed6-4e5f-b38b-51bae9172a97.mp4

And here's how it looks compiled with libncursesw5-dev correctly installed instead:

tig version 2.5.7
ncursesw version 6.1.20180127
readline version 7.0
PCRE2 version 10.31 2018-02-12

https://user-images.githubusercontent.com/606923/197010343-65f7a82e-a993-4c1e-9ab1-7bdc8023f5ef.mp4

Behavior observed under both Kitty and conhost (Windows cmd). Behavior not reproducible in some other terminal emulators.

I don't think UTF-8 is a factor, at least it shouldn't be as I don't think I see any non-ASCII characters in the output on screen at a glance. If tig is using Unicode/non-ASCII symbols for display/formatting, then it shouldn't if no libncursesw was detected (in which case wide character support would only be used for git messages or file contents containing Unicode characters).

[krobelus]

@mqudsi No idea what's the cause of this issue but it's nice that you're also using Tig :) I use it for all my code archaeology and code review needs. I wanna work on it some more, add new UI features etc. but the code can be quite dense.

[mqudsi]

Hey, hey @krobelus. Nice to bump into you here too - I had to double-check I had the right repository when I ran tig and saw your name come up here as well!

I use tig to see relationships between branches and - most importantly - to navigate backwards in git blame history. The ergonomics aren't the greatest (I'm annoyed by how paging in the left and right hand panes necessarily has different bindings), but it gets the job done.

WRT to the behavior described in this bug: it's old and goes back to 2018. Not sure if bisecting will help, but if I have some time I can give that a try.

[mqudsi]

@koutcher is there a commit that fixes this?

[koutcher]

@mqudsi, sorry I was mistaken by your PR being merged. Note that if the problem happens only with some terminals the problem is unlikely to be in Tig, it rather be in the terminfo description for this terminal. You can try to add a private terminfo entry in ~/.terminfo using infocmp and tic. The terminfo entry for putty in CentOS 6 was really broken, it worked much better with the one from CentOS 7. I don't know about kitty.