Japanese characters is garbled in diff view and cannot discard hunk/line with error

Summary

Japanese characters is garbled in diff view and cannot discard hunk/line with error.

Environment

• Windows 7 (SP1), SourceTree 1.9.6.1
• Windows 10, SourceTree 1.9.6.1 with Embedded Git 2.8.1

Steps to Reproduce

1. Set ‘Default text encoding’ to ‘shift_jis’ in ST (Tools > Options)
2. Create a file encoded with shift_is and commit it in local repo.
3. Edit the file to change a few lines in Japanese.
   
4. ST detects the changes and choose ‘Stage hunk’ (or ‘Stage line’)
5. the characters are garbled in diff view
6. 
7. Then choose ’Discard hunk’ (or ‘Discard line’, Error occurs saying that ‘git apply’ failed with code 1
   

The error is similar with SRCTREEWIN-3810, but setting default encoding doesn’t resolve this problem.

Expected Results

Japanese characters should be shown correctly when specified default encoding.

Actual Results

Japanese characters is garbled and user cannot edit/commit files by hunk.

Workaround

Not found.