Give the alternate screen a Kitty image store of its own #107

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natsukium merged 2 commits from fix/per-screen-image-store into main 2026-10-12 14:37:30 +09:00

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natsukium commented 2026-10-12 13:15:05 +09:00

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Closes #89.

kitty keeps one Kitty image store per screen. felis shared one, so a full-screen program on the alternate screen could free or overwrite the shell's images by clearing its screen, by d=r/d=R, by filling the byte cap, or by reusing an i=.

• The session stashes the primary screen's store with its placements on entering the alternate screen, which starts empty under the same cap. ?47l keeps the alternate screen's store with the buffer it keeps, and the next entry resumes both. The grid's screen-switch effect now says whether a leave keeps the buffer and whether an entry resumed it.
• The client still mirrors one store. A switch removes the placements and deletes the images of the screen left, then re-sends the images and placements of the screen coming up. A mirror of both stores would need a screen field on every image message; re-sending on leave was chosen instead.
• The status report counts both stores against twice the per-screen cap. REQ-1008 is now per screen.
• The upgrade dump carries the saved screens. DUMP_VERSION stays at 2: that version is unreleased, and it moves once per release.
• The mirror property test now also checks that every image the window shows is stored, and toggles ?47.

Closes #89. kitty keeps one Kitty image store per screen. felis shared one, so a full-screen program on the alternate screen could free or overwrite the shell's images by clearing its screen, by `d=r`/`d=R`, by filling the byte cap, or by reusing an `i=`. - The session stashes the primary screen's store with its placements on entering the alternate screen, which starts empty under the same cap. `?47l` keeps the alternate screen's store with the buffer it keeps, and the next entry resumes both. The grid's screen-switch effect now says whether a leave keeps the buffer and whether an entry resumed it. - The client still mirrors one store. A switch removes the placements and deletes the images of the screen left, then re-sends the images and placements of the screen coming up. A mirror of both stores would need a screen field on every image message; re-sending on leave was chosen instead. - The status report counts both stores against twice the per-screen cap. REQ-1008 is now per screen. - The upgrade dump carries the saved screens. `DUMP_VERSION` stays at 2: that version is unreleased, and it moves once per release. - The mirror property test now also checks that every image the window shows is stored, and toggles `?47`.

natsukium added 2 commits 2026-10-12 13:15:05 +09:00

daemon: give the alternate screen a Kitty image store of its own ... 3a46708ada

kitty keeps one image store per screen. felis shared one store across
both, with the primary screen's placements stashed while the alternate
screen was up, so a full-screen program could free the shell's images:
a clear freed every unplaced one, `d=r`/`d=R` reached them by id, the
byte cap's least-recently-used step evicted them, and an `i=` the
program reused overwrote the shell's image outright.

The session now stashes the primary screen's store together with its
placements on `?1049h` and starts the alternate screen with an empty
store under the same cap. The client still mirrors one store: the
switch deletes the screen left behind from it and re-sends the screen
coming up. A mirror holding both stores would spare that re-send but
needs a screen field on every image message and a second store in
every client; the primary screen's images are usually few.

A session can now hold a full store per screen, so the status report
counts both and names twice the per-screen cap as the session's.

The dump's saved-screen field changes shape without a version bump:
dump version 2 is unreleased, and the version moves once per release.

The mirror property now also checks that every placement the window
shows has its image.

Assisted-by: Claude Code

grid, daemon: keep the alternate screen's Kitty images across ?47l ... 5ee9018f0f

`?47l` keeps the alternate buffer so the next `?47h` resumes it, and
kitty keeps that screen's image store with it. The daemon dropped the
alternate store on every leave, so the text came back without its
images.

The screen switch now says whether the leave keeps the alternate
buffer and whether the entry resumed it, and the daemon keeps the
alternate store under the same rule. Taking the rule from the grid
rather than tracking `?47` in the daemon keeps the two from drifting:
RIS and `?1047l`/`?1049l` drop the grid's kept buffer, and an entry
that does not resume it never brings back stale images.

Assisted-by: Claude Code

natsukium force-pushed fix/per-screen-image-store from 5ee9018f0f to 5eb2e960a4 2026-10-12 13:34:41 +09:00 Compare

natsukium force-pushed fix/per-screen-image-store from 5eb2e960a4 to 28030181dc 2026-10-12 13:47:07 +09:00 Compare

natsukium merged commit 51a202f4bb into main 2026-10-12 14:37:30 +09:00

natsukium referenced this pull request from a commit 2026-10-12 14:37:32 +09:00

Merge pull request 'Give the alternate screen a Kitty image store of its own' (#107) from fix/per-screen-image-store into main

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