Fix HttpClientConnection leaking temporary buffer files

HttpClientConnection uses a TemporaryBufferEntity which uses
TemporaryBuffer.LocalFile to buffer an HttpEntity. It was leaking
temporary files if the buffered entities were larger than 1MB since it
failed to destroy the TemporaryBuffer.LocalFile.

Bug: 500079
Change-Id: Ib963e04efc252bdd0420a5c69b1a19181e9e6169
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.http.apache/src/org/eclipse/jgit/transport/http/apache/HttpClientConnection.java

@@ -226,17 +226,25 @@ public class HttpClientConnection implements HttpConnection {
 	}
 
 	private void execute() throws IOException, ClientProtocolException {
-		if (resp == null)
-			if (entity != null) {
-				if (req instanceof HttpEntityEnclosingRequest) {
-					HttpEntityEnclosingRequest eReq = (HttpEntityEnclosingRequest) req;
-					eReq.setEntity(entity);
-				}
-				resp = getClient().execute(req);
-				entity.getBuffer().close();
-				entity = null;
-			} else
-				resp = getClient().execute(req);
+		if (resp != null) {
+			return;
+		}
+
+		if (entity == null) {
+			resp = getClient().execute(req);
+			return;
+		}
+
+		try {
+			if (req instanceof HttpEntityEnclosingRequest) {
+				HttpEntityEnclosingRequest eReq = (HttpEntityEnclosingRequest) req;
+				eReq.setEntity(entity);
+			}
+			resp = getClient().execute(req);
+		} finally {
+			entity.close();
+			entity = null;
+		}
 	}
 
 	public Map<String, List<String>> getHeaderFields() {

org.eclipse.jgit.http.apache/src/org/eclipse/jgit/transport/http/apache/TemporaryBufferEntity.java

@@ -55,7 +55,8 @@ import org.eclipse.jgit.util.TemporaryBuffer;
  *
  * @since 3.3
  */
-public class TemporaryBufferEntity extends AbstractHttpEntity {
+public class TemporaryBufferEntity extends AbstractHttpEntity
+		implements AutoCloseable {
 	private TemporaryBuffer buffer;
 
 	private Integer contentLength;
@@ -106,4 +107,16 @@ public class TemporaryBufferEntity extends AbstractHttpEntity {
 	public void setContentLength(int contentLength) {
 		this.contentLength = new Integer(contentLength);
 	}
+
+	/**
+	 * Close destroys the associated buffer used to buffer the entity
+	 *
+	 * @since 4.5
+	 */
+	@Override
+	public void close() {
+		if (buffer != null) {
+			buffer.destroy();
+		}
+	}
 }