TextureAtlas.clearTexture() guarded on pages[0].currentRow being at the
origin — but merged pages are never written through currentRow, so once a
page merge lands a merged page at index 0, every atlas wipe for the rest
of the session silently no-ops: no content clear, no glyph-cache clear,
no clear-model generation bump. Recoveries degrade to placebo, the glyph
cache grows unboundedly, and the session drifts into a merge-heavy state
where stale vertex data paints the tiny-glyph garble seen after
unfocus-then-paste into Claude Code.
Fixes in @xterm/addon-webgl patch (lib bundles + readable src):
- clearTexture(): guard on any-page-has-glyphs; restore _activePages
after wiping (merges permanently shrink the active set)
- AtlasPage.clear(): reset _glyphs/_usedPixels so wiped pages stop
distorting merge-candidate selection
- renderRows merge-retry loop: check the retry budget before
beginFrame() so tripping the limit cannot consume the clear-model
notification and strand a stale model
- GlyphRenderer.render(): clamp texture binds to the sampler budget so
pages overflowing maxAtlasPages cannot TypeError and kill rendering
Verified: two-terminal shared-atlas harness (storm scenario proves the
no-op and its fix; 6-seed adversarial fuzzer clean), 405 unit tests in
pane-manager/atlas-recovery suites, terminal-rendering golden e2e.
Patch @xterm/addon-webgl so clearTexture() and page merge/delete operations
request a model clear and bump a generation counter. Without this, the renderer
keeps drawing glyphs against a stale atlas after the texture is reset, leaving
garbled or blank cells until the next full repaint.
Co-authored-by: Orca <help@stably.ai>
Brennan Benson
Jinjing