1 Commits (freeze-destroyed-consts)

Author	SHA1	Message	Date
Mattias Granlund	0d7b8a6abb	fix: skip derived re-evaluation inside destroyed branch effects ... When a {#if} or {#each} branch is destroyed, derived values inside it must not be re-evaluated — the closure captures state that is now gone, and calling methods on undefined values throws. The crash path: - A parent $derived outside the block reads a child's exported reactive value via bind:this, keeping the inner derived connected in the reactive graph after the branch is torn down - On the next flush, is_dirty() walks the dep chain and calls execute_derived() on the destroyed branch's derived — which crashes The fix checks whether the nearest non-derived ancestor has both DESTROYED and BRANCH_EFFECT flags set, and returns the cached value instead of re-evaluating. This also simplifies the code. Previously get_derived_parent_effect() filtered out destroyed effects (returning null), masking the destroyed state and forcing a second parent-chain walk. Now it returns the raw ancestor unconditionally, execute_derived sets parent_effect to null when destroyed to avoid parenting new effects into a dead scope, and the guard becomes a single flag check with no extra loop. Tested by the if-block-const-destroyed-external-reader component test: an Inner component inside {#if value} exposes its $derived via an exported getProcessed() method; the parent holds a $derived reading it via bind:this outside the block, keeping the inner derived connected. Setting value to undefined triggers the crash path — TypeError without the fix, clean teardown with it.	6 months ago