It turns out that Path.GetFullPath(string) contains undocumented path concatenation logic, taking into account all control characters.
Path.GetFullPath(@"C:\folder\files\escape_this_folder\..//first.doc")
returns C:\folder\files\first.doc
I was expecting an ArgumentException when I called the method, because when I paste such a path into File Explorer, an error pops up saying that the path has wrong format.
Is this behavior described somewhere? Is there any other undocumented logic that could be used and where can I read about it?