Make TJCompressor.close() and TJDecompressor.close() idempotent

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.4.x@1416 632fc199-4ca6-4c93-a231-07263d6284db

ChangeLog.txt

@@ -16,6 +16,13 @@ instead of -1 if width was < 1.
 [5] The Huffman encoder now uses clz and bsr instructions for bit counting on
 ARM64 platforms (see 1.4 beta1 [5].)
 
+[6] The close() method in the TJCompressor and TJDecompressor Java classes is
+now idempotent.  Previously, that method would call the native tjDestroy()
+function even if the TurboJPEG instance had already been destroyed.  This
+caused an exception to be thrown during finalization, if the close() method had
+already been called.  The exception was caught, but it was still an expensive
+operation.
+
 
 1.3.90 (1.4 beta1)
 ==================

java/org/libjpegturbo/turbojpeg/TJCompressor.java

@@ -567,7 +567,8 @@ public class TJCompressor {
    * Free the native structures associated with this compressor instance.
    */
   public void close() throws Exception {
-    destroy();
+    if (handle != 0)
+      destroy();
   }
 
   protected void finalize() throws Throwable {

java/org/libjpegturbo/turbojpeg/TJDecompressor.java

@@ -834,7 +834,8 @@ public class TJDecompressor {
    * Free the native structures associated with this decompressor instance.
    */
   public void close() throws Exception {
-    destroy();
+    if (handle != 0)
+      destroy();
   }
 
   protected void finalize() throws Throwable {