Fixup printing record name in case of unknown sid

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1691312 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/poi/hssf/record/RecordInputStream.java

@@ -52,9 +52,17 @@ public final class RecordInputStream implements LittleEndianInput {
 	public static final class LeftoverDataException extends RuntimeException {
 		public LeftoverDataException(int sid, int remainingByteCount) {
 			super("Initialisation of record 0x" + Integer.toHexString(sid).toUpperCase()
-					+ "(" + RecordFactory.getRecordClass(sid).getSimpleName() + ") left " + remainingByteCount 
+					+ "(" + getRecordName(sid) + ") left " + remainingByteCount 
 					+ " bytes remaining still to be read.");
 		}
+
+        private static String getRecordName(int sid) {
+            Class<? extends Record> recordClass = RecordFactory.getRecordClass(sid);
+            if(recordClass == null) {
+                return null;
+            }
+            return recordClass.getSimpleName();
+        }
 	}
 
 	/** Header {@link LittleEndianInput} facet of the wrapped {@link InputStream} */

src/testcases/org/apache/poi/hssf/record/TestRecordInputStream.java

@@ -94,4 +94,12 @@ public final class TestRecordInputStream extends TestCase {
 		String actual = in.readString();
 		assertEquals("Multilingual - \u591A\u8A00\u8A9E", actual);
 	}
+
+	public void testLeftoverDataException() {
+	    // just ensure that the exception is created correctly, even with unknown sids
+	    new RecordInputStream.LeftoverDataException(1, 200);
+	    new RecordInputStream.LeftoverDataException(0, 200);
+        new RecordInputStream.LeftoverDataException(999999999, 200);
+	    new RecordInputStream.LeftoverDataException(HeaderRecord.sid, 200);
+	}
 }