Database Cache: Fix full database cache rebuild dropping variant and composed property values (closes #21863, #21882)

[AndyButland]

Description

Fixes a regression introduced in 17.2 (PR #21207) where the "Rebuild Database Cache" dashboard action produces empty or incomplete property values in the cmsContentNu table. Per-content-type rebuilds (triggered by saving a content type) were unaffected.

Addresses #21882, #21863.

The problem

When "Rebuild Database Cache" is clicked in Settings > Published Status, DatabaseCacheRebuilder calls Rebuild([], [], []) with empty arrays, meaning "rebuild all content types." Two methods in DatabaseCacheRepository mishandled this empty input affecting variant and composition properties:

1. GetPropertyInfoByContentType had an early return when contentTypeIds was empty, returning an empty dictionary. Without property type metadata, BuildPropertyDataDictionary treated every property as invariant (variation = 0). The downstream filter if (effectivelyVariesByCulture || string.IsNullOrEmpty(cultureCode)) then dropped all culture-specific property values because effectivelyVariesByCulture was always false and culture codes were non-empty.

2. GetCompositionHierarchy iterated over contentTypeIds to resolve compositions and hence failed to load properties inherited from composition types.

A secondary issue existed in DocumentCacheService and MediaCacheService: ClearMemoryCacheAsync (the "Reload Memory Cache" button) cleared the HybridCache but not the _publishedContentCache ConcurrentDictionary. This meant stale converted IPublishedContent objects continued to be served until an app restart.

The fix

• GetPropertyInfoByContentType: When contentTypeIds is empty, fetch all content type IDs from the database and use those as the effective set, rather than returning early. This matches the pattern already used by GetContentTypeVariations.
• GetCompositionHierarchy: When contentTypeIds is empty, iterate over all child IDs found in the composition table (directParents.Keys) instead of the empty input.
• ClearMemoryCacheAsync: Call _publishedContentCache.Clear() before clearing the HybridCache in both DocumentCacheService and MediaCacheService.

Testing

Existing and issue specific tests for this regression should pass.

#21882 provides a good description of the problem and sample project that can be used for manual testing.

[Copilot]

Pull request overview

This PR fixes critical bugs in the database cache rebuild functionality that caused data loss during full cache rebuilds triggered from the Umbraco dashboard. The fix ensures that variant properties, composed properties, and the secondary published content cache are all correctly handled during rebuild operations.

Changes:

• Fixed GetPropertyInfoByContentType to fetch all content type IDs when called with empty collection (full rebuild scenario), preventing variant properties from being dropped
• Fixed GetCompositionHierarchy to handle full rebuild scenario by resolving compositions for all child types when the input collection is empty
• Fixed ClearMemoryCacheAsync in both DocumentCacheService and MediaCacheService to clear the secondary _publishedContentCache dictionary, preventing stale content from being served
• Added comprehensive integration tests covering invariant content, variant culture-specific properties, and composed properties during full rebuild

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/Umbraco.Tests.Integration/Umbraco.PublishedCache.HybridCache/DocumentCacheServiceTests.cs	Added three integration tests to verify full rebuild correctly handles invariant content, variant properties, and composed properties; added IDatabaseCacheRebuilder service accessor for testing full rebuild path
src/Umbraco.PublishedCache.HybridCache/Services/MediaCacheService.cs	Added _publishedContentCache.Clear() call at the start of ClearMemoryCacheAsync to prevent serving stale cached content
src/Umbraco.PublishedCache.HybridCache/Services/DocumentCacheService.cs	Added _publishedContentCache.Clear() call at the start of ClearMemoryCacheAsync to prevent serving stale cached content
src/Umbraco.PublishedCache.HybridCache/Persistence/DatabaseCacheRepository.cs	Modified GetPropertyInfoByContentType to fetch all content type IDs when input is empty; updated GetCompositionHierarchy to handle empty input by using all child IDs from composition table

[Zeegaan]

Looks good and tests good, especially love the integration tests 🚀

[AndyButland]

Cherry-picked into release/17.2.1.