There are three actual changes in this commit:
1. When the trailing newline of a file is removed in a diff, the
change will now be reported with `GIT_DIFF_LINE_DEL_EOFNL` passed
to the callback. Previously, the `ADD_EOFNL` constant was given
which was just an error in my understanding of when the various
circumstances arose. `GIT_DIFF_LINE_ADD_EOFNL` is deprecated and
should never be generated. A new newline is simply an `ADD`.
2. Rewrote the `diff_delta__merge_like_cgit` function that contains
the core logic of the `git_diff_merge` implementation. The new
version doesn't actually have significantly different behavior,
but the logic should be much more obvious, I think.
3. Fixed a bug in `git_diff_merge` where it freed a string pool
while some of the string data was still in use. This led to
`git_diff_print_patch` accessing memory that had been freed.
The rest of this commit contains improved documentation in `diff.h`
to make the behavior and the equivalencies with core git clearer,
and a bunch of new tests to cover the various cases, oh and a minor
simplification of `examples/diff.c`.
This is a major reorganization of the diff code. This changes
the diff functions to use the iterators for traversing the
content. This allowed a lot of code to be simplified. Also,
this moved the functions relating to outputting a diff into a
new file (diff_output.c).
This includes a number of other changes - adding utility
functions, extending iterators, etc. plus more tests for the
diff code. This also takes the example diff.c program much
further in terms of emulating git-diff command line options.
* Implemented git_diff_index_to_tree
* Reworked git_diff_options structure to handle more options
* Made most of the options in git_diff_options actually work
* Reorganized code a bit to remove some redundancy
* Added option parsing to examples/diff.c to test most options
This fixes several bugs, updates tests and docs, eliminates the
FILE* assumption in favor of printing callbacks for the diff patch
formatter helpers, and adds a "diff" example function that can
perform a diff from the command line.
