rega's heap snapshots (leak-722ac7789): Simple Research and All People Groups
mounted twice went 54.2 MB to 65.1 MB, with live Vue apps 6 to 8. Every unmounted
application was still there, one copy per mount, and the retainers were all the
same shape -- a window key set during setup and never cleared. The closure keeps
its component, the component keeps its shadow root, and a whole app survives its
own unmount. An element property dies with the element; a window key does not.
The named one was window.__doxaLogoOwner -> Map -> div.rm-map-canvas -> ShadowRoot
-> app, released only when the map's 'remove' event fires. That listener cannot be
the guarantee the global is cleared, because it only runs if remove() is reached;
it is a consequence of the guarantee, not the guarantee itself. useMapInstance now
drops the claim inside destroy(), before removing, so it goes even if remove()
throws part-way.
As for why remove() was never reached: research-map's unmount hook ran ten
teardown steps and called destroy() last, and two of those steps were unguarded
calls into other composables. A single throw anywhere above stranded the map, and
with it the app. I could not reproduce which step threw without a browser, so the
fix does not depend on knowing: each step is isolated and destroy() runs from a
finally, where nothing above it can skip it. Ordering teardown so the most
important step is last, behind nine chances to fail, was the real defect.
The globals themselves are released by the components that set them -- four verify
hooks in research-map, three in the dashboard map panel, the vocabulary hook in
the grid, which had no unmount hook at all. Released as SETS: __rdashPinAt was the
one the snapshot named, but __rdashMap holds the map and retains strictly more, so
clearing only the reported one would have looked fixed and leaked nearly as much.
The deletes are written one per line instead of looped over an array of names, so
that the check can read them. A release a checker cannot see is worth no more than
no release, the day someone removes three of the four.
The check flags only values that actually retain. A warn-once boolean latch and a
page-wide cache keyed off itself are deliberate and must not be reported, or it
becomes noise and gets switched off. It is NOT in gates:pre: 19 sites remain in
other owners' plugins, and this is a fleet pattern rather than one plugin's bug.
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