## Summary
Fixes#20053
When a server sends zstd-compressed data with chunked transfer encoding,
each chunk may be compressed as a separate zstd frame. Previously, Bun's
zstd decompressor would stop after the first frame, causing responses to
be truncated at 16KB.
## The Fix
The fix modifies the zstd decompressor (`src/deps/zstd.zig`) to continue
decompression when a frame completes but input data remains. When
`ZSTD_decompressStream` returns 0 (frame complete), we now check if
there's more input data and reinitialize the decompressor to handle the
next frame.
## Testing
Added regression tests in `test/regression/issue/20053.test.ts` that:
1. Test multi-frame zstd decompression where two frames need to be
concatenated
2. Simulate the exact Hono + compression middleware scenario from the
original issue
Both tests fail without the fix (truncating at 16KB) and pass with the
fix.
## Verification
```bash
# Without fix (regular bun):
$ bun test test/regression/issue/20053.test.ts
0 pass
2 fail
# With fix (debug build):
$ bun bd test test/regression/issue/20053.test.ts
2 pass
0 fail
```
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
