[release/10.0] Fix 'ordinal -1 is invalid' crash when a nested JSON complex sub-collection grows

[Copilot]

Fixes #38299

Description
EF Core 10 introduced an issue in complex-type change tracking. When an entity maps 2+ ComplexProperty columns with ToJson(), and a nested JSON collection item defines 2+ List sub-collection properties, growing one of those sub-collections between load and save causes SaveChangesAsync to throw InvalidOperationException: Complex entry original ordinal '-1' is invalid ... as it's outside of the collection of length '1'. Root cause: InternalEntryBase.SetPropertyModified's recurse loop forced every flattened complex-collection element — including newly Added ones (whose original ordinal is legitimately -1) — to Modified/Unchanged, which then failed ValidateOrdinal(original: true). The fix skips Added complex entries in that loop (leaving their state as computed by change detection), mirroring the guard already present in the bulk InternalComplexCollectionEntry state-change path.

Customer impact
Customers using JSON-mapped complex types with the common "upsert" pattern (load a tracked entity, map incoming data onto it via Mapperly/AutoMapper/manual assignment, then SaveChanges) cannot save when a nested sub-collection grows — SaveChanges throws and the update is lost. There is no clean workaround for real upsert scenarios short of detaching/reattaching or avoiding any growth in nested collections.

How found
Customer reported on 10.0.7. The issue has 4 reactions (3 👍), indicating more than one affected customer.

Regression
No. Complex collection support was introduced in EF Core 10.0.

Testing
Added Grow_nested_sub_collection_in_complex_property_mapped_to_json to the relational ComplexCollectionJsonUpdateTestBase. Also verified end-to-end against a standalone repro matching the issue's model in both directions.

Risk
Low. The change is a narrow guard that skips Added complex entries during the recurse state-forcing loop, mirroring logic already present in the bulk state-change path. It is gated behind the Microsoft.EntityFrameworkCore.Issue38299 quirk switch, so the prior behavior can be restored via AppContext switch if a regression is discovered.

[Copilot]

Pull request overview

Fixes an ordinal -1 is invalid crash in EF Core change tracking when nested JSON-mapped complex sub-collections grow between load and save, by preventing Added complex entries (which legitimately have no original ordinal) from being forced into Modified/Unchanged during recursive state propagation.

Changes:

• Updated InternalEntryBase.SetPropertyModified(..., recurse: true) to skip Added flattened complex entries (behind Microsoft.EntityFrameworkCore.Issue38299 quirk switch).
• Added a relational specification test covering a deep JSON complex graph where one nested sub-collection grows (with a sibling sub-collection present).
• Added SQLite functional test override with SQL baseline for the new scenario.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/EFCore/ChangeTracking/Internal/InternalEntryBase.cs	Skips Added complex entries during recursive state propagation to avoid invalid original-ordinal validation.
src/EFCore/ChangeTracking/Internal/InternalEntryBase.InternalComplexCollectionEntry.cs	Introduces UseOldBehavior38299 AppContext switch to gate the new behavior.
test/EFCore.Relational.Specification.Tests/Update/ComplexCollectionJsonUpdateTestBase.cs	Adds deep JSON model + regression test exercising nested sub-collection growth.
test/EFCore.Sqlite.FunctionalTests/Update/ComplexCollectionJsonUpdateSqliteTest.cs	Adds provider override asserting the SQL update for the new test.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

[AndriySvyryd]

@artl93

[artl93]

Approved. Customer reported in new scenario. Added quirk.