Symbol drawing into adjacent blank cells

Feature ID: text-symbol-whitespace-expansion. Type: feature.

Manual tests: just probe text-symbol-whitespace-expansion opens this feature's scenarios.

Browse under Text, emoji and rendering / Emoji artwork and fallback. A scenario may exercise related features; its existence does not establish support.

Specification and related documentation

• text/emoji-rendering.md
• Ghostty: constraintWidth in src/renderer/cell.zig (implementation reference; no standard describes this) ghostty-symbol-constraint-width

Terminal compatibility

Missing records mean unknown. as-of identifies the assessed version or revision, not the first release to support a feature.

Terminal	Support	As of	Notes and evidence
Alacritty	Unknown	Unversioned	No assessment recorded.
Apple Terminal	Unknown	Unversioned	No assessment recorded.
ConPTY (conhost)	Unknown	Unversioned	No assessment recorded.
Contour	Unknown	Unversioned	No assessment recorded.
DomTerm	Unknown	Unversioned	No assessment recorded.
foot	Unknown	Unversioned	No assessment recorded.
Ghostty	Unknown	Unversioned	No assessment recorded.
iTerm2	Unknown	Unversioned	No assessment recorded.
kitty	Unknown	Unversioned	No assessment recorded.
Konsole	Unknown	Unversioned	No assessment recorded.
mintty	Unknown	Unversioned	No assessment recorded.
mlterm	Unknown	Unversioned	No assessment recorded.
PuTTY	Unknown	Unversioned	No assessment recorded.
Revenant	Unsupported	git:bd0bcf50b695349486aa227fe482e6c6a7c23798	Current policy is strict in-cell fitting. A one-cell symbol is drawn inside the cells the backend committed to it; an oversized monochrome face is shrunk to fit rather than allowed to grow into a neighboring blank cell, and the artwork gate asserts that the following cell, the row below and the border above stay free of ink. Adopting the optional behavior later would be an opt-in with its own eligibility, background, selection, cursor and damage rules; this record describes the present default rather than a decision against it. Assessed from the containment assertions only, which do not cover legibility. Checked 2026-09-20. test
RLogin	Unknown	Unversioned	No assessment recorded.
st	Unknown	Unversioned	No assessment recorded.
tmux	Unknown	Unversioned	No assessment recorded.
rxvt-unicode	Unknown	Unversioned	No assessment recorded.
VTE	Unknown	Unversioned	No assessment recorded.
wayst	Unknown	Unversioned	No assessment recorded.
WezTerm	Unknown	Unversioned	No assessment recorded.
Windows Terminal	Unknown	Unversioned	No assessment recorded.
xterm	Unknown	Unversioned	No assessment recorded.
xterm.js	Unknown	Unversioned	No assessment recorded.