D3212: patch: implement a new worddiff algorithm

[quark (Jun Wu)]

quark added inline comments.

INLINE COMMENTS

> spectral wrote in color.py:94
> I understand the reasoning for wanting `diff.inserted` and `diff.inserted.changed` to be the same color, but unfortunately I think it might not be super feasible in upstream.
> 
> 'dim' support in my terminfo database (and via testing) is actually pretty common among the biggest terminals; for oddities, I'm seeing:
> 
> - the linux console (very few people use it) has weird support
> - screen simulates it with underline, tmux passes it through (so I don't see it)
> - rxvt-unicode doesn't support it
> - the terminfo profile for cygwin doesn't indicate support for it
> - Apple's terminal advertises itself as xterm-compatible and seems to support it
> - iTerm2 similarly
> 
> I'm willing to be convinced it's OK, especially since this mode isn't the default.  @dhduvall originally wrote the "not supported by many terminals" bit, I wonder if they have any suggestions.  @indygreg has also dealt with terminal issues (and deals with windows more than me, so might know more there).

There are not many choices - dim, 16/256 colors, or bold. We ended up with 16/256 colors internally for wider support (ex. tmux). But I'd like to express my (strong) options that:

- diff.inserted.changed and diff.inserted are same
- diff.inserted is not bold

in this patch. Because color.py has no 16/256 support yet (and if it does detection conservatively, most terminals will only report 8 color support). And the only remaining choice is "dim". For weird terminals like tmux, I think it's their bugs to fix, not this patch.

That said, I'm fine with changing the defaults to whatever. So feel free to send follow-ups changing it.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3212

To: quark, #hg-reviewers, durin42, yuja
Cc: indygreg, dhduvall, yuja, spectral, mercurial-devel