CODEC-134: Add test to cover missed exception case in BCodec.java.

Author: tmousaw-ptc

src/test/java/org/apache/commons/codec/net/BCodecTest.java

@@ -34,6 +34,12 @@
  * @version $Id$
  */
 public class BCodecTest {
+    private static final String[] BASE64_IMPOSSIBLE_CASES = {
+            "ZE==",
+            "ZmC=",
+            "Zm9vYE==",
+            "Zm9vYmC=",
+    };
 
     static final int SWISS_GERMAN_STUFF_UNICODE[] =
         { 0x47, 0x72, 0xFC, 0x65, 0x7A, 0x69, 0x5F, 0x7A, 0xE4, 0x6D, 0xE4 };
@@ -148,4 +154,17 @@ public void testDecodeObjects() throws Exception {
             // Exception expected, test segment passes.
         }
     }
+    
+    @Test
+    public void testBase64ImpossibleSamples() {
+        BCodec codec = new BCodec();
+        for (String s : BASE64_IMPOSSIBLE_CASES) {
+            try {
+                codec.decode(s);
+                fail();
+            } catch (DecoderException ex) {
+                // expected
+            }
+        }
+    }
 }