fix(android): per-call temp file to close concurrent verify->install race - #4
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…race loadVerifiedFromUrl spawned a thread per call and every call shared one fixed temp path (verified-bundle.jsbundle.tmp). Under two overlapping calls, call B's delete+recreate at that path swapped the file out from under call A between A's streaming hash and A's renameTo(target): A's digest still matched its own (orphaned-inode) bytes, but the rename promoted B's partial/unverified file onto the canonical bundle — breaking the 'canonical path only ever holds verified bytes' invariant the temp-then-promote design establishes. Download to a per-call File.createTempFile temp instead, cleaned up in a finally. Each call now verifies and renames its own file, so the canonical path only ever receives a fully verified bundle regardless of concurrency. iOS is unaffected (it hashes the in-memory NSData and atomically writes those same bytes). Adds a regression test asserting distinct temps per call.
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Overview
Fixes a concurrency race in the Android verified-install path, raised in review of the consuming app's bump PR (ExodusMovement/exodus#44443).
loadVerifiedFromUrlspawns a thread per call, and every call shared one fixed temp path (verified-bundle.jsbundle.tmp). With two overlapping calls, call B'sdelete()+ recreate at that path swaps the file out from under call A between A's streaming hash and A'srenameTo(target): A still writes to its now-orphaned inode so its digest matches its own bytes, but the rename promotes B's partial/unverified file onto the canonical bundle — breaking the "canonical path only ever holds verified bytes" invariant the temp-then-promote design is meant to establish.Fix: download to a per-call
File.createTempFile(...)temp, cleaned up in afinally. Each call verifies and renames its own file, so the canonical path only ever receives a fully verified bundle regardless of concurrency.iOS is unaffected — it hashes the in-memory
NSDataand atomically writes those exact verified bytes (no shared-path promotion).No version bump here — the version will be bumped in a separate commit after merge (same as the hardening PR), then published.
Verification
concurrentCallsUseDistinctTempsSoTargetOnlyHoldsVerifiedBytesregression guard.verifyAndInstalllogic and its existing cases are unchanged; only the caller's temp allocation + cleanup changed.