fix(draw): avoid negative cursor-left in vertical_seq#235
Merged
Tieske merged 3 commits intolunarmodules:mainfrom Mar 27, 2026
Merged
fix(draw): avoid negative cursor-left in vertical_seq#235Tieske merged 3 commits intolunarmodules:mainfrom
Tieske merged 3 commits intolunarmodules:mainfrom
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Tieske
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Mar 24, 2026
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Apr 2, 2026
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Fix the
terminal.draw.line.vertical_seq()so it does not generate invalid ANSI whenlastcolumn=true.Problem :
In
src/terminal/draw/line.lua,vertical_seq()used:cursor.position.left_seq(w - lastcolumn * 2)For a 1-column character (for example "|") and lastcolumn=true, this becomes left_seq(-1), which emits invalid ANSI like \27[-1D.
Fix :
Clamp the computed back-move before calling left_seq():
compute back = w - lastcolumn * 2
if back < 0, set back = 0
Tests added :
Updated spec/12-draw_spec.lua with regression tests:
vertical_seq(3, "|", true)no longer emits negative left movement.vertical_seq(3, "|", false)keeps existing normal behavior.Impact :
Prevents invalid cursor movement sequences at terminal right edge and avoids rendering glitches in vertical line / border drawing.