next.js

61f08530 - [turbopack] Fix a crash under turbopackPersistentCaching (#82592)

[turbopack] Fix a crash under turbopackPersistentCaching (#82592) Address a crash found at head when testing caching while switching back and forth from `dev` and `build`. ``` thread '<unnamed>' panicked at turbopack/crates/turbo-persistence/src/db.rs:798:17: attempt to subtract with overflow stack backtrace: 0: __rustc::rust_begin_unwind 1: core::panicking::panic_fmt 2: core::panicking::panic_const::panic_const_sub_overflow 3: <core::iter::adapters::map::Map<core::slice::iter::Iter<alloc::vec::Vec<<turbo_persistence::db::TurboPersistence>::compact_internal::SstWithRange>>, <turbo_persistence::db::TurboPersistence>::compact_internal::{closure#2}> as core::iter::traits::iterator::Iterator>::fold::<(), core::iter::traits::iterator::Iterator::for_each::call<alloc::vec::Vec<smallvec::SmallVec<[usize; 1]>>, <alloc::vec::Vec<alloc::vec::Vec<smallvec::SmallVec<[usize; 1]>>>>::extend_trusted<core::iter::adapters::map::Map<core::slice::iter::Iter<alloc::vec::Vec<<turbo_persistence::db::TurboPersistence>::compact_internal::SstWithRange>>, <turbo_persistence::db::TurboPersistence>::compact_internal::{closure#2}>>::{closure#0}>::{closure#0}> 4: <alloc::vec::Vec<alloc::vec::Vec<smallvec::SmallVec<[usize; 1]>>> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<alloc::vec::Vec<smallvec::SmallVec<[usize; 1]>>, core::iter::adapters::map::Map<core::slice::iter::Iter<alloc::vec::Vec<<turbo_persistence::db::TurboPersistence>::compact_internal::SstWithRange>>, <turbo_persistence::db::TurboPersistence>::compact_internal::{closure#2}>>>::from_iter 5: <turbo_persistence::db::TurboPersistence>::compact ``` Scenario: * build turbopack and next * cd bench/module-cost * enable persistent caching * pnpm i * pnpm dev-turbopack * load localhost:3000 and click all the buttons * pnpm build-turbopack * pnpm dev-turbopack * load localhost:3000 and see the crash ## What? The `get_merge_segments` function and its caller had a different idea about what `max_merge_segment_count` means. Unify how this is accounted to avoid underflow.