Someone needs to make a script which runs through a git repo's commit history and looks for commits which add invisible Unicode characters. Maybe some existing exploits could be found in the wild.
exp="\u2060|\u200b|\u2061|\u2062|\u2063|\u200c|\u200d"
git log -p --pickaxe-regex -S"$exp"Spaces, tabs, and newlines can be used to alter code in invisible way.