HTTPCLIENT-1312: Zero length content entities with a Content-Encoding header cause an I/O error when an attempt is made to consume such entity

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1440673 13f79535-47bb-0310-9956-ffa450edef68

RELEASE_NOTES.txt

@@ -1,7 +1,11 @@
 Changes since 4.3 ALPHA1
 -------------------
 
-* [HTTPCLIENT-1313] Fixed IllegalStateException in deprecated ThreadSafeClientConnManager
+* [HTTPCLIENT-1312] Zero length content entities with a Content-Encoding header cause 
+  an I/O error when an attempt is made to consume such entity.
+  Contributed by Oleg Kalnichevski <olegk at apache.org>
+
+* [HTTPCLIENT-1313] Fixed IllegalStateException in deprecated ThreadSafeClientConnManager.
   Contributed by Oleg Kalnichevski <olegk at apache.org>
 
 * [HTTPCLIENT-1305] Ensure chunking is disabled when applying Base64 encoding.

httpclient/src/main/java/org/apache/http/client/protocol/ResponseContentEncoding.java

@@ -73,8 +73,9 @@ public class ResponseContentEncoding implements HttpResponseInterceptor {
             final HttpContext context) throws HttpException, IOException {
         final HttpEntity entity = response.getEntity();
 
-        // It wasn't a 304 Not Modified response, 204 No Content or similar
+        // entity can be null in case of 304 Not Modified, 204 No Content or similar
-        if (entity != null) {
+        // check for zero length entity.
+        if (entity != null && entity.getContentLength() != 0) {
             final Header ceheader = entity.getContentEncoding();
             if (ceheader != null) {
                 final HeaderElement[] codecs = ceheader.getElements();

httpclient/src/test/java/org/apache/http/client/protocol/TestResponseContentEncoding.java

@@ -82,6 +82,21 @@ public class TestResponseContentEncoding {
         Assert.assertTrue(entity instanceof GzipDecompressingEntity);
     }
 
+    @Test
+    public void testGzipContentEncodingZeroLength() throws Exception {
+        final HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, 200, "OK");
+        final StringEntity original = new StringEntity("");
+        original.setContentEncoding("GZip");
+        response.setEntity(original);
+        final HttpContext context = new BasicHttpContext();
+
+        final HttpResponseInterceptor interceptor = new ResponseContentEncoding();
+        interceptor.process(response, context);
+        final HttpEntity entity = response.getEntity();
+        Assert.assertNotNull(entity);
+        Assert.assertTrue(entity instanceof StringEntity);
+    }
+
     @Test
     public void testXGzipContentEncoding() throws Exception {
         final HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, 200, "OK");