buffer renamed "expand(" on save

This issue has plagued me for years in MacVim and I have not been able to identify the source. It is intermittent, and occurs roughly 1 every 100 hundred saves (so probably 2 or 3 times per day). I cannot say what triggers it but I have not been able to make it go away. Any advice or fix gratefully received.

What happens:

• I hit <D-s> to save current buffer, which is already associated with a filename
• the buffer is not saved
• current buffer is magically renamed expand(, the contents are unaffected
• editing continues as normal (If I try to save again, then a new file called expand( is saved to disk).

Environment

• Vim version 8.2
• MacOS 11.6
• Terminal: GUI

まず、macOS 11.6 上の Vim 8.2 を使用する MacVim で、名前付きバッファーに対して を使い、断続的な保存動作を再現します。バッファーの名前が expand( に変更される前後の保存パスと GUI の処理を調査します。問題を発生させたときに、元のバッファーがファイル名との関連付けを維持し、正しく保存されれば完了です。