  Forking structure is widespread in the open-source repositories and that
causes a significant number of merge conflicts. In this paper, we study the
problem of textual merge conflicts from the perspective of Microsoft Edge, a
large, highly collaborative fork off the main Chromium branch with significant
merge conflicts. Broadly, this study is divided into two sections. First, we
empirically evaluate textual merge conflicts in Microsoft Edge and classify
them based on the type of files, location of conflicts in a file, and the size
of conflicts. We found that ~28% of the merge conflicts are 1-2 line changes,
and many resolutions have frequent patterns. Second, driven by these findings,
we explore Program Synthesis (for the first time) to learn patterns and resolve
structural merge conflicts. We propose a novel domain-specific language (DSL)
that captures many of the repetitive merge conflict resolution patterns and
learn resolution strategies as programs in this DSL from example resolutions.
We found that the learned strategies can resolve 11.4% of the conflicts (~41%
of 1-2 line changes) that arise in the C++ files with 93.2% accuracy.
