Unclear difference between short direct and indirect lines in jj log graph

[samueltardieu]

In the repository available here, I was surprised by the difference in the output of the two jj log commands:

$ jj log -T 'change_id.shortest() " [" branches "] " commit_id.shortest()'
@  muuq [] fdc3
o          vtrk [] 079e
├─┬─┬─┬─╮
o │ │ │ │  nzun [issue-10331] e4e5
│ o │ │ │  yvls [issue-10304] 657e
├─╯ │ │ │
│   o │ │  mylus [issue-10339] 48a0
├───╯ │ │
│     o │  kloo [issue-10296*] c97d
├─────╯ │
│       o  lxxxv [issue-10241*] 9324
├───────╯
o  uoru [auto* master*] 6356
│
~
$ jj log -T 'change_id.shortest() " [" branches "] " commit_id.shortest()' -r master:issue-10304
o  yvls [issue-10304] 657e
o  qlnw [] e9d
o  nkqk [] 1fec
o  xwost [] c231
o  uoru [auto* master*] 6356
│
~

The first command makes it look like master is a parent of issue-10304, while the second one shows that this is not the case, there are three extra commits in the middle. The first output is confusing.

[martinvonz]

I don't know how we would present that more clearly. That little line segment (─╯) seems too short that coloring it differently would make it clear enough. I think part of the problem is also that the line then merges into the leftmost line, which is a direct line between nzun and uoru. Maybe we could decide not let direct/parent and indirect/ancestor edges share a line. I don't know how much that would complicate the graph, but maybe it's worth it. Maybe @markbt has thoughts? Has this come up at Meta?

[martinvonz]

Maybe this is also a good place to mention the related problem of making dashed lines clearer when they're a single row high. Maybe a different glyph or a different color would help there.

[joyously]

For accessibility reasons, relying on color to convey information is not a good idea (7% of men are red-green color blind).
Also, are there two sets of default colors, one for dark mode and one for light mode? I saw a question in another project about how the default colors were not legible in their terminal with their choice of a solarized color scheme.