FULL PRODUCT VERSION :


ADDITIONAL OS VERSION INFORMATION :
Ubuntu 14.04

A DESCRIPTION OF THE PROBLEM :
Hotspot constucts nameless parameter with empty name ("") that leads to verification error in reflection code (MalformedParametersException in Executable.verifyParameters)

hotspot code in reflection.cpp:
oop Reflection::new_parameter(Handle method, int index, Symbol* sym,
                              int flags, TRAPS) {
  Handle name;

  // A null symbol here translates to the empty string
  if(NULL != sym) {
    name = java_lang_String::create_from_symbol(sym, CHECK_NULL);
  } else {
    name = java_lang_String::create_from_str("", CHECK_NULL);
  }
 ....
}

Verification in Executable.verifyParameters:
...
    if (name != null) {
                if (name.isEmpty() || name.indexOf('.') != -1 ||
                    name.indexOf(';') != -1 || name.indexOf('[') != -1 ||
                    name.indexOf('/') != -1) {
                    throw new MalformedParametersException("Invalid parameter name \"" + name + "\"");
                }
            }
...

NB: there is special workaround in Parameter.getName() with special empty name processing case:
public String getName() {
        // Note: empty strings as paramete names are now outlawed.
        // The .equals("") is for compatibility with current JVM
        // behavior.  It may be removed at some point.
        if(name == null || name.equals(""))
            return "arg" + index;
        else
            return name;
    }


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Generate method parameters metadata with null parameters names and then try to extract them via Method.getParameters()

ACTUAL -
java.lang.reflect.MalformedParametersException: Invalid parameter name ""

REPRODUCIBILITY :
This bug can be reproduced always.