ADDITIONAL SYSTEM INFORMATION :
Windows 7 / OpenJDK 11.02

A DESCRIPTION OF THE PROBLEM :
If you do something like this, in earlier Version in return C:\IPC now it Returns C:IPC
File f = new File ("C:", "IPC");
String path =f.getPath();

The Problem occurs in Java.io.WinNtFilesystem in the resolve method on line 239:

        boolean isDirectoryRelative =
            pn == 2 && isLetter(parent.charAt(0)) && parent.charAt(1) == ':';



REGRESSION : Last worked in version 8u192

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
File f = new File ("C:", "IPC");
String path =f.getPath();

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
path = C:\IPC
ACTUAL -
path = C:IPC

FREQUENCY : always