Abort Merge on a single file always results in a parameter error message

What steps will reproduce the problem?

1. Begin a merge which results in conflicts.
2. Resolve conflicts on one of the files.
3. On the same file, select TortoiseGit-->Abort Merge

What is the expected output? What do you see instead?

The selected file should be returned to its post-merge, conflicted state. Instead, an error dialog appears: "The parameters '/path' and '/pathfile' are mutually exclusive. You must only specify one of them."

What version of TortoiseGit and Git are you using? On what operating system?

Duplicated in two environments:

• TortoiseGit 2.7.0.0, git version 2.18.0.windows.1, Windows 7 Pro SP1 64-bit
• TortoiseGit 2.7.1.0 (20181021-7f2d0004), git version 2.17.0.windows.1, Windows 10 Enterprise Version 1803 64-bit

Please provide any additional information below.

The same error message will occur regardless of whether changes or conflicts occurred on the file.