The commit graph used '⏣' (U+23E3 BENZENE RING WITH CIRCLE) for merge
commits and '◯' (U+25EF LARGE CIRCLE) for regular commits. Both have
very poor coverage in popular monospace fonts:
- '⏣' lives in the Misc Technical block and is essentially absent from
every common monospace font (Source Code Pro, JetBrains Mono, Fira
Code, Cascadia Code, Hack, Iosevka, Menlo, Consolas, Monaco, IBM
Plex Mono, Ubuntu Mono, Noto Sans Mono, Inconsolata). It is always
drawn from a system fallback font.
- '◯' is the late-addition LARGE CIRCLE codepoint. It is present in
some fonts (Cascadia, Fira Code, Hack, Iosevka, Menlo, Noto Sans
Mono) but missing from many others, including Source Code Pro and
most Nerd Font derivatives based on it.
This is why the graph renders inconsistently across platforms even
when the same monospace font is configured: each OS picks a different
fallback font (Apple Symbols on macOS, Segoe UI Symbol on Windows,
Noto/DejaVu/Symbola on Linux), and the substituted glyphs differ in
shape, weight, and advance width. '◯' is also East Asian Ambiguous
width, so some terminals render it wider than one cell, exaggerating
the misalignment.
Replace the symbols with codepoints from the foundational 1991
Geometric Shapes block, which has far broader font coverage:
- Merge: '◎' U+25CE BULLSEYE -- concentric circles, the visually
closest cousin to the previous benzene-ring glyph.
- Commit: '○' U+25CB WHITE CIRCLE -- the same hollow-circle silhouette
as before, just a more universally available codepoint.
The new symbols are present in the font directly in significantly
more cases; and when fallback is still required, they are universally
well-drawn (unlike '⏣', which many fallback fonts also lack).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This saves some memory at the cost of a slight performance increase (I suppose
reallocting the slice when adding new Pipes is slightly more expensive now).
Performance of the BenchmarkRenderCommitGraph benchmark is 130μs before, 175μs
after. I'm guessing this is still acceptable.
This in itself is not an improvement, because hashes are unique (they are shared
between real commits and rebase todos, but there are so few of those that it
doesn't matter). However, it becomes an improvement once we also store parent
hashes in the same pool; but the real motivation for this change is to also
reuse the hash pointers in Pipe objects later in the branch. This will be a big
win because in a merge-heavy git repo there are many more Pipe instances than
commits.
In go 1.22, loop variables are redeclared with each iteration of the
loop, rather than simple updated on each iteration. This means that we
no longer need to manually redeclare variables when they're closed over
by a function.
Changing globals in the init() function of a test file is a bad idea, as it
affects all other tests that run after it. Do it explicitly in each test
function that needs it, and take care of restoring the previous value
afterwards.
The root commit is special in that it has no parents. So we need to add a pipe that's headed for a commit
that doesn't actually exist i.e. the mythical empty tree commit. We're using the actual hash of that
pseudo-commit, but it's not being read anywhere.
