Unnamed repository; edit this file 'description' to name the repository. https://git.b0n.dev/jellyfin/atom?h=master 2026-07-21T06:51:30Z 2026-07-21T06:51:30Z zerafachris christopher.zerafa@blocklabs.io 2026-07-21T06:51:30Z urn:sha1:53e58d8b1b61c44405322bf91a8aa230f02b8323 Addresses review feedback from @Bond-009 on PR #17370: the test helper InvokeUpdateItem was invoking the private UpdateItem(BaseItemDto, BaseItem) method via reflection. Jellyfin.Api.csproj already grants InternalsVisibleTo("Jellyfin.Api.Tests"), so the method is changed to internal and the test now calls it directly, removing the GetMethod/Invoke boilerplate. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> 2026-07-17T15:20:30Z zerafachris christopher.zerafa@blocklabs.io 2026-07-17T15:20:30Z urn:sha1:5cd3d7ebb7c8ce5b7cf68b0696543780215a6fff BaseItemDto.Genres, .Tags, and .ProviderIds are plain auto-properties with no default initializer, so they deserialize to null when a client omits them from a partial POST /Items/{itemId} body. The OpenAPI spec documents every BaseItemDto field as optional, but ItemUpdateController.UpdateItem fed these three properties straight into Distinct()/Select()/ToList() without a null check, so a request that (for example) only sets Tags throws ArgumentNullException("source") once it reaches the unguarded Genres line, before Tags is even processed. Guard all three assignments with the same "if (request.X is not null)" pattern already used for the neighboring Studios/Taglines/ProductionLocations fields in this method, so omitted fields are left unchanged instead of crashing the request. Adds ItemUpdateControllerTests covering the reported repro (only Tags supplied) and a companion case asserting existing Genres/ProviderIds are preserved when omitted from the payload. Signed-off-by: zerafachris <christopher.zerafa@blocklabs.io>