## Bug Fix
**Issue**: When using `brain.import(filePath, { preserveSource: true })`,
binary files (PDFs, images, Excel) were NOT being preserved in VFS, causing
Z_DATA_ERROR when trying to read them back.
**Root Cause**: ImportCoordinator line 444 checked for `type === 'buffer'`,
but normalizeSource() returns `type: 'path'` for file paths (the most common
case). This caused `sourceBuffer = undefined`, silently failing to preserve
the source file.
**Fix**: Changed condition to `Buffer.isBuffer(normalizedSource.data)` to
handle both Buffer objects and file paths correctly.
## Code Changes
**src/import/ImportCoordinator.ts:445**
```typescript
// BEFORE (v5.1.1)
sourceBuffer: normalizedSource.type === 'buffer' ? normalizedSource.data as Buffer : undefined
// AFTER (v5.1.2)
sourceBuffer: Buffer.isBuffer(normalizedSource.data) ? normalizedSource.data as Buffer : undefined
```
## Testing
Added comprehensive tests in `tests/unit/import/preserve-source-fix.test.ts`:
- ✅ File path import with preserveSource: true (main fix)
- ✅ Verify preserveSource: false works correctly
- ✅ Binary file integrity (no corruption)
## Impact
**Before**: Workshop team experienced Z_DATA_ERROR reading imported PDFs
**After**: Binary files correctly preserved and readable from VFS
## Related Issues
Fixes bug reported in:
/media/dpsifr/storage/home/Projects/brain-cloud/apps/workshop/BRAINY_BUG_REPORT.md
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
David Snelling
97eb6eec2c