[Teamviewer 13.1.3629] - Can't use Alt gr special characters on remote host in mintty

Hello everyone,

I'm just here to file a bug report and haven't found any issue tracker link or some such. If there is an issue tracker that I haven't found please feel free me to tell me where it is.

Okay, so the situation is:
I connect from a Windows 7 computer to another Windows 7 computer and start a Cygwin terminal or a git bash (of git for Windows), meaning I'm running a Cygwin mintty terminal OR a git bash MSYS2/MinGW64 mintty terminal.

While in the mintty terminal, Alt gr special characters (~, {, }, etc.) aren't printed 99% of the time. This seems to happen because when running Teamviewer, pressing Alt gr results in a VK_CONTROL down followed by a VK_MENU down. I'm no expert, but the Windows standard seems to be that the timestamps of both keypresses have to be the same, but while using Teamviewer, the timestamps can be slightly different which leads to mintty not recognizing the press of Alt gr.

This is already recorded in the mintty issue tracker under this issue. The developer advised me to file a bug here.