Under the hood
Diff and log output can now render gutter (line-number margin) and content as separate arrays
What
The internal code that renders lines for diffs and logs (things like line numbers and change markers) can now return its output split into two parallel pieces: one array for the 'gutter' (the margin showing line numbers or markers) and one for the actual content, via a new renderSplit method. When no gutter width is set, it still returns a single combined lines array as before.
Why
Separating gutter and content lets the display line the two up more precisely, which should help diff and log views render more accurately when columns need to align.