A FAULT-TOLERANT THREE-WAY MERGE FOR XML AND HTML

摘要

Three-way merging is a technique that is used to reintegrate changes to a document when multiple independently modified copies have been made. Tools for three-way merge of ASCII text files exist in the form of the ubiquitous diff and patch tools, but these are of limited applicability when parts of the documents have been rearranged. Our fault-tolerant three-way merge for XML and HTML was designed to support rearrangements to document structure, as well as situations where the well-formedness of the document has been lost. This is achieved by taking a text-based approach that recognizes moved text and uses normalization and denormalization of whitespace. As there are many possibilities for merging moved text we decided to base the design of the merge on principles derived from a set of use cases, which systematically explore different merging situations. This design process should help ensure that the chosen merge is useful from a practical point of view.