Files::isWritable returns false for the created directory if run this code on Windows and a created directory is on a mounted network Solaris drive.

MiniTest
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File workDirAsFile = new File("Z:\\links\\fury-home\\temp\\wd_win\\test_wd");
workDirAsFile.mkdir();
System.out.println(Files.isWritable(workDirAsFile.toPath()));
workDirAsFile.delete();
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In this MiniTest "Z:" is mounted network drive with Solaris OS, "Z:\\links\\fury-home\\temp\\wd_win" has 777 permissions.
Checked with b135.

For details of failed test see JCK-7306336.