Refactoring-Aware Patch Integration Across Structurally Divergent Java Forks

2025-08-08

AI Summary

Patch integration frequently fails across long-lived forked Java variants due to structural divergences—especially refactorings such as renaming, moving, and restructuring—that break patch applicability. Method: This paper proposes RePatch, a technique that enables cross-variant patch migration by reverse-aligning refactorings with patch context and replaying them in the target variant to restore semantic correctness. Built upon the RefMerge framework, RePatch integrates semantics-aware refactoring detection and bidirectional mapping to achieve fine-grained contextual alignment while preserving repair intent. Contribution/Results: Evaluated on 478 real-world fix requests, conventional cherry-picking fails in 64.4% of cases; RePatch successfully recovers 52.8% of these failures, substantially enhancing the reusability of defect fixes across structurally heterogeneous, asymmetric variants.

Technology Category

• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Machine Learning: Feature Construction/Reformulation
• Natural Language Processing: Code Generation / Program Synthesis from Natural Language

Application Category

• Graph Algorithms and Modeling for the Web: Representation, reconstruction, and subgraph or motif discovery in Web-related graphs
• Search and Retrieval-Augmented AI: Multilingual and cross-lingual Web search
• Semantics and Knowledge: Scalable techniques for the creation, curation, publication, maintenance, and consumption of large, Web-based, structured, reusable, knowledge graphs and ontologies

Abstract

While most forks on platforms like GitHub are short-lived and used for social collaboration, a smaller but impactful subset evolve into long-lived forks, referred to here as variants, that maintain independent development trajectories. Integrating bug-fix patches across such divergent variants poses challenges due to structural drift, including refactorings that rename, relocate, or reorganize code elements and obscure semantic correspondence. This paper presents an empirical study of patch integration failures in 14 divergent pair of variants and introduces RePatch, a refactoring-aware integration system for Java repositories. RePatch extends the RefMerge framework, originally designed for symmetric merges, by supporting asymmetric patch transfer. RePatch inverts refactorings in both the source and target to realign the patch context, applies the patch, and replays the transformations to preserve the intent of the variant. In our evaluation of 478 bug-fix pull requests, Git cherry-pick fails in 64.4% of cases due to structural misalignments, while RePatch successfully integrates 52.8% of the previously failing patches. These results highlight the limitations of syntax-based tools and the need for semantic reasoning in variant-aware patch propagation.

Problem

• Integrating bug-fix patches across divergent Java forks
• Addressing structural drift and refactoring challenges
• Enhancing patch success rate with semantic reasoning

Innovation

• Refactoring-aware patch integration system
• Inverts refactorings to realign patch context
• Supports asymmetric patch transfer for variants