6.4.0 to 6.4.9 
C:\cygwin\home\thauser\eap\jboss-eap-6.4.0\jboss-eap-6.4\bin>jboss-cli.bat "--command=patch apply ..\..\..\jboss-eap-6.4.9-patch.zip"
{
    "outcome" : "success",
    "result" : {}
}
Press any key to continue . . .



Patched 6.4.9 to 6.4.15
C:\cygwin\home\thauser\eap\jboss-eap-6.4.0\jboss-eap-6.4\bin>
C:\cygwin\home\thauser\eap\jboss-eap-6.4.0\jboss-eap-6.4\bin>jboss-cli.bat "--command=patch apply ..\..\..\jboss-eap-6.4.15-patch.zip"
{
    "outcome" : "success",
    "result" : {}
}
patching exception



6.4.9-full-build to 6.4.15
C:\cygwin\home\thauser\eap\jboss-eap-6.4.9-full-build\jboss-eap-6.4\bin>jboss-cli.bat "--command=patch apply ..\..\..\jboss-eap-6.4.15-patch.zip --override-all"
{
    "outcome" : "success",
    "result" : {}
}
patching exception
Press any key to continue . . .

C:\cygwin\home\thauser\eap\jboss-eap-6.4.9-full-build\jboss-eap-6.4\bin>echo %errorlevel%
1