Repository.Commits.QueryBy is missing changes

Reproduction steps

This seems to have been brought up a couple of times already (a quick search showed #1401, #1591, https://github.com/libgit2/libgit2sharp/pull/963#issuecomment-355674649).

This is pretty weird: QueryBy returns 0 LogEntries, while going through all commits and diffing to the previous one shows the same changes/additions/renames as e.g. the SourceTree or Fork UI for the exact same path as for the QueryBy call.

Note that it only does that for some files, most files work fine. I haven't found a common pattern so far (e.g. specific characters, or only merges, or ...) but it looks like QueryBy is omitting merges and that might cause problems.

(commits in reverse order)

Expected behavior

QueryBy should return all changes to the file (as outlined in #963 where it was originally added).

Actual behavior

QueryBy returns 0 LogEntries.

Version of LibGit2Sharp (release number or SHA1)

git2-106a5f2

Operating system(s) tested; .NET runtime tested

Win 10, .NET 4.6

EDIT: Maybe I'm understanding the code wrong, but taking a quick peek at https://github.com/libgit2/libgit2sharp/blob/master/LibGit2Sharp/Core/FileHistory.cs#L137, I think QueryBy in fact ignores all commits that have more than 1 parent (e.g. all merges).

Bắt đầu bằng cách tái hiện các LogEntries bị thiếu cho đường dẫn bị ảnh hưởng trên Windows/.NET 4.6, đồng thời so sánh QueryBy với phương pháp diff trên tất cả các commit được mô tả trong issue. Đọc LibGit2Sharp/Core/FileHistory.cs quanh dòng 137, tập trung vào cách các commit có nhiều parent được xử lý. Được xem là hoàn thành khi QueryBy trả về mọi thay đổi của tệp bị ảnh hưởng, bao gồm cả các thay đổi liên quan đến merge.