Expose the Minimal diff algorithm

[tomcsmith1990]

This adds the Minimal diff algorithm and uses it if specified when doing a diff, fixing #1057.

Unfortunately it's difficult to find an example which produces a different diff output for the Meyers and Minimal algorithm, so I don't have a unit test to check 1dd11be. It looks like the libgit code suffered the same problem and only test that output from patience differs from the default, which is already checked in UsingPatienceAlgorithmCompareOptionProducesPatienceDiff.

The change could be tested by extracting a class from Diff.BuildOptions and checking that the GitDiffOptions returned have the correct flags set, but that does break the encapsulation slightly. I'm happy to make that change if you want though.

[nulltoken]

@tomcsmith1990 Neat! One nitpick though. Would you mind melding those two commits together into an atomic/cohesive one?

Unfortunately it's difficult to find an example which produces a different diff output for the Meyers and Minimal algorithm, so I don't have a unit test to check 1dd11be. It looks like the libgit code suffered the same problem and only test that output from patience differs from the default, which is already checked in UsingPatienceAlgorithmCompareOptionProducesPatienceDiff.

Duh. If I remember correctly I also searched for a simple example, in vain.

@peff Would you know more about this?

[nulltoken]

Fix #1057

[peff]

When in doubt, throw CPU at the problem:

$ cd git
$ git log -p --diff-algorithm=myers >myers
$ git log -p --diff-algorithm=minimal >minimal
$ diff myers minimal | less

This comes up with lots of examples in the translation files, which are quite hard to read (for instance, git/git@82aa9b7). We can try it restricted only to *.c. That turns up only a single commit, git/git@d18f76d, which is pretty much a giant unreadable diff no matter how you slice it.

So no, I guess I don't really have any good examples.

[nulltoken]

@peff ❤️ for this amazing answer!

[tomcsmith1990]

@nulltoken thanks, I've squashed the commits down into one.

[nulltoken]

💥

Cheers!