feat: diff algorithm is controlled by git configuration diff.algorithm

Author: Byron

Diff for: git-repository/src/object/tree/diff.rs

@@ -110,21 +110,22 @@ pub mod change {
 
     impl<'old, 'new> DiffPlatform<'old, 'new> {
         /// Perform a diff on lines between the old and the new version of a blob.
+        /// The algorithm is determined by the `diff.algorithm` configuration.
         /// Note that the [`Sink`][git_diff::text::imara::Sink] implementation is
         /// what makes the diff usable and relies heavily on what the caller requires, as created by `make_sink`.
-        pub fn lines<FnS, S>(&self, algorithm: git_diff::text::Algorithm, make_sink: FnS) -> S::Out
+        pub fn lines<FnS, S>(&self, new_sink: FnS) -> S::Out
         where
             FnS: for<'a> FnOnce(&git_diff::text::imara::intern::InternedInput<&'a [u8]>) -> S,
             S: git_diff::text::imara::Sink,
         {
             git_diff::text::with(
                 self.old.data.as_bstr(),
                 self.new.data.as_bstr(),
-                algorithm,
+                git_diff::text::Algorithm::Myers, // TODO: use diff.algorithm
                 // TODO: make use of `core.eol` and/or filters to do line-counting correctly. It's probably
                 //       OK to just know how these objects are saved to know what constitutes a line.
                 git_diff::text::imara::intern::InternedInput::new,
-                make_sink,
+                new_sink,
             )
             .1
         }

Diff for: git-repository/tests/object/tree.rs

@@ -35,9 +35,7 @@ mod diff {
                     .diff()
                     .expect("changed file")
                     .expect("objects available")
-                    .lines(git::diff::text::Algorithm::Myers, |_| {
-                        git_diff::text::imara::sink::Counter::default()
-                    });
+                    .lines(|_| git_diff::text::imara::sink::Counter::default());
                 assert_eq!(count.insertions, 1);
                 assert_eq!(count.removals, 0);
                 Ok(Default::default())

Diff for: src/plumbing/progress.rs

@@ -280,6 +280,10 @@ static GIT_CONFIG: &[Record] = &[
             deviation: None,
         },
     },
+    Record {
+        config: "diff.algorithm",
+        usage: Planned { note: Some("to be used when doing line diffs") },
+    },
     Record {
         config: "extensions.objectFormat",
         usage: InModule {