Record: use a local copy, and say when there is nothing newer

Outcome

Two behaviours were added to the Update path:

if the offered file is already beside the installed one, the update verifies it and uses it instead of downloading it again;
when the check finds nothing newer, Status declares You already are using the latest version. in bold and the Update button is disabled.

Both were verified live against FreeCAD 1.1.3 through the installed tool, and both are covered by the test suite.

Using What Is Already There

apply_update computed the destination — the offered file’s own name in the directory of the file being updated — and then always downloaded. It now checks that destination first:

destination exists, and is not the file being replaced	verify it exactly as a download would be verified, make it executable, and use it in place; nothing is fetched
destination exists but does not verify	refuse, naming the file and saying to remove it to download the offered file instead — a working file is never replaced by a broken local one
destination is the file being replaced	the ordinary download path, because the local file is the old one

The verification is the same function the download path uses, so the published digest and the file’s own .sha256_sig still decide. The reporting says which happened: used the copy already at … against downloaded from …, and --dry-run names the local file rather than a URL.

This is the case that matters in practice: a newer AppImage downloaded by hand into the managed directory, or an earlier integration’s file, sitting next to the one in use. It saves the whole transfer — 820 MB for FreeCAD.

Nothing Newer

on_update() already asked the tool what the transport offers. Now the answer decides the panel:

Check result	Status	Update button
`same` or `same-file`	bold You already are using the latest version.	disabled
`older`	bold The release is older than the version you are using.	disabled
an update is available	the download starts	insensitive while it runs
the check could not be made	the reason, as before	left enabled, because a network failure is not an answer

The bold line is a GtkTextTag on the Status buffer, applied after the text is set the same way the Discovered tab emphasises This run and Error. Clearing it happens when an update starts or succeeds, so a window that has just installed something does not keep claiming to be up to date on the file it replaced.

The test hooks grew two lines for this: === status in bold === and === disabled ===, so a driven run reports both without changing the === buttons: row every other test reads.

Fixing the Installer on the Way

make install failed with Text file busy: an activator window was open, and cp writes the destination in place. scripts/program-install.sh now copies to a temporary name and renames it over the destination, which is atomic and leaves a running copy with the file it started from. This is the ordinary case for a tool that installs itself an activator.

Live Verification

appimage-activator --activate update on the installed FreeCAD_1.1.3-…AppImage, driven through ~/.local/bin/appimage-integrate, printed === status in bold === / You already are using the latest version. / === disabled === Update.
The FreeCAD integration itself is now 1.1.3, integrated and properly integrated, with the launcher, TryExec and the Update item all naming ~/Applications/FreeCAD_1.1.3-Linux-x86_64-py311.AppImage, and 1.1.1 preserved as FreeCAD_1.1.1-…AppImage.previous. An update on the real desktop completed at 16:09 and did exactly what this feature set describes — the new file under its own name, the replaced file kept — which also means it was that update, not a hand edit, that changed the FreeCAD launcher from the 1.1.1 that the previous record found. With the local-copy rule now installed, the same click would have used the file that was already there instead of downloading it.

Verification

Verified 2026-09-23 with make test; all twenty test scripts passed.

tests/99-update-apply.sh gained two sections: an offered file that is already present is used, with the local file becoming the one in use, the launcher retargeted, and the replaced file kept as .previous — proved by pointing the transport at a URL that serves no AppImage, so a download would have failed; and a local copy that is not an AppImage is refused with the file named and the working file untouched.

tests/95-activator-ui.sh gained the same and same-file cases, asserting the exact bold line, the disabled Update button, and that nothing was downloaded.

Commits

59195cd Use an offered file that is already there, and say when nothing is newer