Fixed JVM crash due to EXCEPTION_ACCESS_VIOLATION

"The function get_java_var_long() in SerialImp.c casts the Java-long-value to a long in case of type == 'J'. But Java-Long is 64 bit and C-long is only 32 bit. Later this long is cast to a 64-bit-memory-address -> crash. A possible solution is to return always size_t instead of long."

NeuronRobotics#131
NeuronRobotics#133
NeuronRobotics#135

src/main/c/include/SerialImp.h

@@ -472,7 +472,7 @@ int translate_parity( JNIEnv *, tcflag_t *, jint );
 void system_wait();
 void finalize_event_info_struct( struct event_info_struct * );
 int read_byte_array( JNIEnv *, jobject *, int, unsigned char *, int, int );
-long get_java_var_long( JNIEnv *, jobject, char *, char * );
+size_t get_java_var_long( JNIEnv *, jobject, char *, char * );
 size_t get_java_var( JNIEnv *, jobject, char *, char * );
 jboolean is_interrupted( struct event_info_struct * );
 int send_event(struct event_info_struct *, jint, int );

src/main/c/src/SerialImp.c

@@ -5075,9 +5075,9 @@ size_t get_java_var( JNIEnv *env, jobject jobj, char *id, char *type ) {
   return (size_t) get_java_var_long( env, jobj, id, type );
 }
 
-long get_java_var_long( JNIEnv *env, jobject jobj, char *id, char *type )
+size_t get_java_var_long( JNIEnv *env, jobject jobj, char *id, char *type )
 {
-	long result = 0;
+	size_t result = 0;
 	jclass jclazz = (*env)->GetObjectClass( env, jobj );
 	jfieldID jfd = (*env)->GetFieldID( env, jclazz, id, type );
 
@@ -5092,7 +5092,7 @@ long get_java_var_long( JNIEnv *env, jobject jobj, char *id, char *type )
 		return result;
 	}
 	if ( !strcmp( type, "J" ) ) {
-	  result = (long)( (*env)->GetLongField( env, jobj, jfd ) );
+	  result = (size_t)( (*env)->GetLongField( env, jobj, jfd ) );
 	} else {
 	  result = (size_t) ( (*env)->GetIntField( env, jobj, jfd ) );
 	}