Fix LINQ Append/Prepend GetCount overflow to throw OverflowException#123821

Merged

stephentoub merged 3 commits intomainfrom

copilot/optimize-linq-getcount-implementation

Jan 31, 2026

Commits on Jan 30, 2026

Initial plan
Copilot
committed
Add checked arithmetic to AppendPrepend GetCount methods and add overflow tests

Copilot
and
vcsjones
committed
Fix overflow tests to use mock collection instead of allocating huge arrays

Copilot
and
vcsjones
committed