Ignore LARGE_COMMUNITY with length 0

Author: omuravskiy

src/main/java/org/javamrt/mrt/Attributes.java

@@ -249,10 +249,12 @@ private void decode(byte[] record, int attrLen, int attrBytes)
 				this.hasASPATHLimit = true;
 				break;
 
-                        case MRTConstants.LARGE_COMMUNITY:
-                                Attribute largeCommunity = new LargeCommunity(buffer);
-                                attributes.set(MRTConstants.ATTRIBUTE_LARGE_COMMUNITY, largeCommunity);
-                                break;
+				case MRTConstants.LARGE_COMMUNITY:
+					if (buffer.length > 0) {
+						Attribute largeCommunity = new LargeCommunity(buffer);
+						attributes.set(MRTConstants.ATTRIBUTE_LARGE_COMMUNITY, largeCommunity);
+					}
+					break;
 
 				default:
 					route_btoa.System_err_println("Ignoring unknown attribute type " + type);

src/test/java/org/javamrt/mrt/LargeCommunitiesTest.java

@@ -3,17 +3,18 @@
 
 import org.testng.annotations.Test;
 
-import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertTrue;
-import static org.testng.Assert.assertNull;
-
-import java.io.*;
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.Base64;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertNull;
+
 public class LargeCommunitiesTest {
     @Test
     public void testParseDump()
@@ -57,4 +58,19 @@ public void testParseDump()
         assertEquals(strings.size(), 1);
         assertEquals(strings.iterator().next(), "200753:200:46524131");
     }
+
+    @Test
+    public void should_parse_large_community_with_zero_length() throws Exception {
+        final String base64 = "X3+NoAAQAAQAAACRAADjuwAAMW4AAAABW840glvONP3/////////////////////AH0CADwYF4YQGBeGERgXlyEYF6mgGBerYBhAwAAYQMABGEDAAhhAwAMYQMAEGEDABRhybOsYcmz4GLYSyBi2EskAJkABAQBAAg4CAwAA47sAABsbAAB+BUADBFvONILACATjuwPo4CAAGJ73ew==";
+        final byte[] bytes = Base64.getDecoder().decode(base64);
+        final BGPFileReader bgpFileReader = new BGPFileReader(new ByteArrayInputStream(bytes));
+        MRTRecord mrtRecord = null;
+        MRTRecord tmp;
+        while (!bgpFileReader.eof()) {
+            tmp = bgpFileReader.readNext();
+            if (tmp != null) mrtRecord = tmp;
+        }
+        assertEquals(mrtRecord.getClass(), Advertisement.class);
+        assertEquals(mrtRecord.toString(), "BGP4MP|1602194848|A|91.206.52.130|58299|158.247.123.0/24|58299 6939 32261|IGP|91.206.52.130|0|0|58299:1000|NAG||");
+    }
 }