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>
BeginInteractiveRebaseForCommit is used for all the patch commands, and for
rewording. It works by setting the commit we want to stop at to 'edit'; this
doesn't work for merge commits. This wasn't a problem for the patch commands so
far, because you typically don't use custom patches with merge commits (although
we don't prevent this; maybe we should?).
However, it was a problem when you tried to reword a merge commit; this
previously failed with an error, as the test added in the previous commit
demonstrated.
Also, we want to add a new patch command that has to stop *before* the selected
commit (pull patch to new commit before the original one), and this wouldn't
work for the first commit in a feature branch, because it would have to set the
last commit before that to 'edit', which isn't possible if that's a merge (which
is likely).
To fix all this, use a 'break' before the selected commit if the commit is a
merge. It is important that we only do it in that case and not always, otherwise
we would break the new regression tests that were added a few commits ago.
