From ea1b6e8ed57bf67b21873abc90adaaa532d1828f Mon Sep 17 00:00:00 2001
From: William S Fulton <wsf@fultondesigns.co.uk>
Date: Thu, 23 Apr 2015 19:17:35 +0100
Subject: [PATCH] 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 #386
---
 CHANGES.current   | 3 +++
 Lib/java/java.swg | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGES.current b/CHANGES.current
index 24c36d6a0..4fc30370a 100644
--- a/CHANGES.current
+++ b/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).
 
diff --git a/Lib/java/java.swg b/Lib/java/java.swg
index e7e041d13..9374f5783 100644
--- a/Lib/java/java.swg
+++ b/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 */