Ein zweiter Blick auf deinen Code

Review the following [language/framework] code for correctness. Intended behavior: [describe behavior]. Focus on reproducible bugs, boundary cases, unsafe input handling, and resource cleanup. For each finding, give the affected function or line, the input that triggers the problem, its practical impact, and a minimal fix. Distinguish verified issues from questions that need more context. Do not invent APIs or rewrite unrelated code. Finish with the smallest useful set of tests.

[Paste code here]