Most automatic program repair techniques rely on test cases to specify correct program behavior. Due to test cases' frequently incomplete coverage of desired behavior, however, patches often overfit and fail to generalize to broader requirements. Moreover, in the absence of perfectly correct outputs, methods to ensure higher patch quality, such as merging together several patches or a human evaluating patch recommendations, benefit from having access to a diverse set of patches, making patch diversity a potentially useful trait. We evaluate the correctness and diversity of patches generated by GenProg and an invariant-based diversity-enhancing extension described in our prior work. We find no evidence that promoting diversity changes the correctness of patches in a positive or negative direction. Using invariant- and test case generation-driven metrics for measuring semantic diversity, we find no observed semantic differences between patches for most bugs, regardless of the repair technique used.

中文翻译：

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基于不变引导搜索的程序修复的补丁质量和多样性

大多数自动程序修复技术依赖于测试用例来指定正确的程序行为。然而，由于测试用例经常不完整地覆盖所需的行为，补丁经常过度拟合并且无法推广到更广泛的需求。此外，在没有完全正确的输出的情况下，确保更高补丁质量的方法，例如将多个补丁合并在一起或人工评估补丁推荐，受益于访问不同的补丁集，使补丁多样性成为潜在有用的特征。我们评估了 GenProg 生成的补丁的正确性和多样性，以及我们之前工作中描述的基于不变性的多样性增强扩展。我们没有发现任何证据表明促进多样性会在积极或消极的方向上改变补丁的正确性。