`Session::history_budget` (default `default_history_budget()`) caps the
memory the undo steps of all open documents keep together. After each
command, tool edit, interaction commit, direct edit, framed script run
and closed undo group, `Session::trim_histories` drops the oldest steps
of any document first, undo steps before redo steps. Each document keeps
its last eight undo steps and next eight redo steps, and a held history
keeps all of its steps. While a script runs or an undo group is open,
no steps are dropped, so a canceled group leaves the other documents'
steps in place. Closing a document frees its share. The steps are not
counted again while neither the budget nor any history changed. Each
document's own `byte_budget` stays as its ceiling.
Undo, Redo and a canceled undo group put back an earlier document but
left the Variables panel highlight as it was. After renaming the
highlighted variable and undoing, the highlight still named the new
name: a variable defined later under that name showed highlighted
without a click, and Delete removed it.
Each of these paths now clears a highlight whose variable the restored
document does not define, as Delete Variables and Load Variable Library
already did.
A Shape Builder click or drag over a selection of more than 128
segments merged on the UI thread, so the app stopped drawing and
answering until the merge was done. The tool now computes such a
merge on another thread from the map it built for the hover.
Meanwhile the canvas keeps drawing, the touched regions stay
highlighted and the pointer is the busy pointer. When the merge is
done, the tool runs shapeBuilder.merge with the gesture's params as
one undo step, and the command takes the computed shapes when it
would compute the same ones. The web build merges in the command, as
before.
A press while the map is still being built no longer waits for it on
the UI thread: the tool records the gesture and makes it once the map
is there.
Clicks, drags and the Shape Builder's arrow keys made during the
merge, and commands, menu items, the app's own dialogs, saves and tool
or document switches, run after it on the merged art; engine queries
that only read run at once. A change to the selected paths made
outside a command drops the merge. The headless host and ui.pointer
reply once the merge is applied.
The Shape Builder and the Live Paint Bucket keep their map of the
selection over a new revision of the document when the selected paths
and their outlines are unchanged, instead of building it again.
dotCooCoo