refactor: use <revision_sha>^ instead of <revision_parent_sha> as base revsion when getting changes of commit (#1625)

Signed-off-by: leo <[email protected]>

Author: love-linger

src/ViewModels/CommitDetail.cs

@@ -354,7 +354,7 @@ private void Refresh()
 
             Task.Run(async () =>
             {
-                var parent = _commit.Parents.Count == 0 ? Models.Commit.EmptyTreeSHA1 : _commit.Parents[0];
+                var parent = _commit.Parents.Count == 0 ? Models.Commit.EmptyTreeSHA1 : $"{_commit.SHA}^";
                 var cmd = new Commands.CompareRevisions(_repo.FullPath, parent, _commit.SHA) { CancellationToken = token };
                 var changes = await cmd.ReadAsync().ConfigureAwait(false);
                 var visible = changes;