Please support convert UTF8-MAC (NFD) to UTF8 (NFC) in commit message

Steps
=====

1. Init git repo and commit first one (Terminal.app)
$ git init test
$ cd test
$ touch hello
$ git add .
$ git commit -m "がぎぐげご"

2. Make some changes
$ touch hello2
$ git add .

3. Open test repo with SourceTree
4. Commit changes (step2) with comment "がぎぐげご"

Probrem
=======

Commit message is same but different encoding

Step1: がぎぐげご (UTF8)
Step4: がぎぐげご (UTF8-MAC)

Expect
======

Step1: がぎぐげご (UTF8)
Step2: がぎぐげご (UTF8)

Info
====
First letter: が
NFC: U+304C (HIRAGANA LETTER GA)
NFD: U+304B U+3099 (HIRAGANA LETTER KA + COMBINING KATAKANA-HIRAGANA VOICED SOUND)

Attached:

• Test repo
• Windows cmd.exe

Please support convert UTF8-MAC (NFD) to UTF8 (NFC)

or

Don't change commit message encoding.