| merge API | 
 | ========= | 
 |  | 
 | The merge API helps a program to reconcile two competing sets of | 
 | improvements to some files (e.g., unregistered changes from the work | 
 | tree versus changes involved in switching to a new branch), reporting | 
 | conflicts if found.  The library called through this API is | 
 | responsible for a few things. | 
 |  | 
 |  * determining which trees to merge (recursive ancestor consolidation); | 
 |  | 
 |  * lining up corresponding files in the trees to be merged (rename | 
 |    detection, subtree shifting), reporting edge cases like add/add | 
 |    and rename/rename conflicts to the user; | 
 |  | 
 |  * performing a three-way merge of corresponding files, taking | 
 |    path-specific merge drivers (specified in `.gitattributes`) | 
 |    into account. | 
 |  | 
 | Data structures | 
 | --------------- | 
 |  | 
 | * `mmbuffer_t`, `mmfile_t` | 
 |  | 
 | These store data usable for use by the xdiff backend, for writing and | 
 | for reading, respectively.  See `xdiff/xdiff.h` for the definitions | 
 | and `diff.c` for examples. | 
 |  | 
 | * `struct ll_merge_options` | 
 |  | 
 | Check merge-ll.h for details. | 
 |  | 
 | Low-level (single file) merge | 
 | ----------------------------- | 
 |  | 
 | Check merge-ll.h for details. |