## Summary
- Fixed buffer overflow in env_loader when parsing large environment
variables with escape sequences
- Replaced fixed 4096-byte buffer with a stack fallback allocator that
automatically switches to heap allocation for larger values
- Added comprehensive tests to prevent regression
## Background
The env_loader previously used a fixed threadlocal buffer that could
overflow when parsing environment variables containing escape sequences.
This caused crashes when the parsed value exceeded 4KB.
## Changes
- Replaced fixed buffer with `StackFallbackAllocator` that uses 4KB
stack buffer for common cases and falls back to heap for larger values
- Updated all env parsing functions to accept a reusable buffer
parameter
- Added proper memory cleanup with defer statements
## Test plan
- [x] Added test cases for large environment variables with escape
sequences
- [x] Added test for values larger than 4KB
- [x] Added edge case tests (empty quotes, escape at EOF)
- [x] All existing env tests continue to pass
fixes#11627
fixes BAPI-1274
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
### What does this PR do?
- for these kinds of aborts which we test in CI, introduce a feature
flag to suppress core dumps and crash reporting only from that abort,
and set the flag when running the test:
- libuv stub functions
- Node-API abort (used in particular when calling illegal functions
during finalizers)
- passing `process.kill` its own PID
- core dumps are suppressed with `setrlimit`, and crash reporting with
the new `suppress_reporting` field. these suppressions are only engaged
right before crashing, so we won't ignore new kinds of crashes that come
up in these tests.
- for the test bindings used to test the crash handler in
`run-crash-handler.test.ts`, disables core dumps but does not disable
crash reporting (because crashes get reported to a server that the test
is running to make sure they are reported)
- fixes a panic when printing source code around an error containing
`\n\r`
- updates the code where we clone vendor tests to checkout the right tag
- adds `vendor/elysia/test/path/plugin.test.ts` to
no-validate-exceptions
- this failure was exposed by starting to test the version of elysia we
have been intending to test. the crash trace suggests it may be fixed by
#21307.
- makes dumping core or uploading a crash report count as a failing test
- this ensures we don't realize a crash has occurred if it happened in a
subprocess and the main test doesn't adequately check the exit code. to
spawn a subprocess you expect to fail, prefer `expect(code).toBe(1)`
over `expect(code).not.toBe(0)`. if you really expect multiple possible
erroneous exit codes, you might try `expect(signal).toBeNull()` to still
disallow crashes.
### How did you verify your code works?
Running affected tests on a Linux machine with core dumps set up and
checking no new ones appear.
https://buildkite.com/bun/bun/builds/21465 has no core dumps.
