This change makes the DiffNotifyCallback always use an "unowned"
*git.Diff that does _not_ run the finalizer. Since the underlying
git_diff object is still owned by libgit2, we shouldn't be calling
Diff.Free() on it, even by accident, since that would cause a whole lot
of undefined behavior.
Now instead of storing a reference to a *git.Diff in the intermediate
state while the diff operation is being done, create a brand new
*git.Diff for every callback invocation, and only create a fully-owned
*git.Diff when the diff operation is done and the ownership is
transfered to Go.
This commit adds barebones capacity to generate diffs from two trees and
to emit those as git-style diffs (via `Patch.String`), or to enumerate
the files/hunks/lines in the diff to emit the data yourself.
The walk functions have been implemented in the same manner as the Odb
walking methods.
Note that not all of the functionality is implemented for either the
`git_diff_*` nor the `git_patch_*` functions, and there are unexposed
constants which would likely be useful to add.
lhchavez
Carlos Martín Nieto
Carlos Martín Nieto
Adam Berkovec
Jose Alvarez
Jesse Ezell
lye