Fixed base64::decode() return "" if input ends with garbase and no padding

src/base64.h

@@ -133,7 +133,11 @@ std::string decode(InputIterator first, InputIterator last)
     for(int i = 1; i <= 4; ++i) {
       k[i] = getNext(first, last, INDEX_TABLE);
       if(k[i] == last) {
-        res.clear();
+        // If i == 1, input may look like this: "TWFu\n" (i.e.,
+        // garbage at the end)
+        if(i != 1) {
+          res.clear();
+        }
         return res;
       } else if(*k[i] == '=' && eq == 0) {
         eq = i;

test/Base64Test.cc

@@ -76,6 +76,9 @@ void Base64Test::testDecode()
   s = "TWFu";
   CPPUNIT_ASSERT_EQUAL(std::string("Man"), base64::decode(s.begin(), s.end()));
 
+  s = "TWFu\n";
+  CPPUNIT_ASSERT_EQUAL(std::string("Man"), base64::decode(s.begin(), s.end()));
+
   s = "TQ==";
   CPPUNIT_ASSERT_EQUAL(std::string("M"), base64::decode(s.begin(), s.end()));