[Bug] Panic: Invalid UTF-8 char boundary in string slicing with multi-byte characters

Question

**Bug Description**
thread '<unnamed>' (119596) panicked at /rustc/ed61e7d7e242494fb7057f2657300d9e77bb4fcb\library\core\src\str\mod.rs:833:21:
byte index 5 is not a char boundary; it is inside '車' (bytes 3..6) of `物車）`
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

**Environment Info**
- Platform: win32
- Terminal: vscode
- Version: 2.0.71
- Feedback ID: cce1e472-fc32-4c22-8526-22ba1662d79d

**Errors**
```json
[]
```