[BUGFIX] Rebuild inline SVG sprite for cached pages when asset cache is lost

[davidsteeb]

Problem

The inline SVG sprite is injected by InlineSvgInjector, which reads the collected SVG files from the tx_assetcollector cache. That cache is separate from the page cache and may even sit on a different backend (e.g. page cache on Redis, tx_assetcollector on the default DB backend).

When the two desync — the asset cache is cleared (or evicted) while the page cache survives — a fully cached page is delivered without the ViewHelpers being re-rendered, so the collector is empty and the sprite is omitted. Result: every icon on the page disappears until the page cache is regenerated. This shows up as “icons missing on the first load(s) after clearing the cache”.

Fix

InlineSvgInjector now scans the response body for referenced icons (<use href="#icon-…">) and re-resolves any that are not collected from an icon registry:

• The registry (icon identifier => SVG file) is built from TypoScript (plugin.tx_assetcollector.icons) while it is available, and persisted in a dedicated cache in the system group — so it survives a pages cache flush and is available to rebuild the sprite in cached frontend scope, where TypoScript is gone.
• It is read lazily — only when the page actually references an uncollected icon — so regular requests pay nothing.
• An empty registry makes the self-heal a no-op, so it can never make rendering worse than before.

Also makes AssetCollector::loadTypoScript() tolerant of cached frontend scope, where FrontendTypoScript::getSetupArray() throws ("Setup array has not been initialized…").

Tests

• Unit: addReferencedIcons() resolves a missing referenced icon from the registry, is a no-op (and does not even invoke the registry provider) when the icon is already collected, and ignores unknown icons.
• Functional: SvgViewHelperSelfHealTest reproduces the desync (page cache kept, tx_assetcollector cache flushed) and asserts the cached page is still delivered with the full sprite.

All existing unit + functional tests pass; php-cs-fixer and phpstan (repo configs) are clean.

🤖 Generated with Claude Code

[achimfritz]

👎
this looks like a workaround for me, how can this occurre?
the asset cache has the same tags as the page-cache.
(btw. you can put the asset-cache into the same backend as the page-cache, i have already done so)

[achimfritz]

not this extension scope.