Memory leak in java directors when passing byte arrays (char*, size_t)

When passing a byte array from c++ to Java using the director feature, the generated jni code does not release a temporary byte array.

This is the typemap specified in Java.swg:

    %typemap(directorin, descriptor="[B") (char *STRING, size_t LENGTH) {
    jbyteArray jb = (jenv)->NewByteArray($2);
    (jenv)->SetByteArrayRegion(jb, 0, $2, (jbyte *)$1);
    $input = jb;
    }

    %typemap(directorargout) (char *STRING, size_t LENGTH)
    %{(jenv)->GetByteArrayRegion($input, 0, $2, (jbyte *)$1); %}

Notice that the call to NewByteArray doesn't contain a symmetric release logic as the SetByteArrayRegion/GetByteArrayRegion does.

Closes swig#386

CHANGES.current

@@ -5,6 +5,9 @@ See the RELEASENOTES file for a summary of changes in each release.
 Version 3.0.6 (in progress)
 ===========================
 
+2015-04-23: wsfulton
+            [Java] Bug #386 - Memory leak fix in (char *STRING, size_t LENGTH) typemaps.
+
 2015-04-23: vadz
             [Python] Make "default" typemap work again (#330, #377).
 

Lib/java/java.swg

@@ -1346,7 +1346,8 @@ SWIG_PROXY_CONSTRUCTOR(true, true, SWIGTYPE)
   $input = jb;
 }
 %typemap(directorargout) (char *STRING, size_t LENGTH)
-%{(jenv)->GetByteArrayRegion($input, 0, $2, (jbyte *)$1); %}
+%{(jenv)->GetByteArrayRegion($input, 0, $2, (jbyte *)$1);
+(jenv)->DeleteLocalRef($input);%}
 %apply (char *STRING, size_t LENGTH) { (char *STRING, int LENGTH) }
 
 /* java keywords */