ByteVector: Skip whitespace in fromBase64 (#1484)

ASCII whitespace (space, tab, CR, LF) is skipped before decoding, so
line-wrapped base64, such as a METADATA_BLOCK_PICTURE wrapped every 76
characters, decodes instead of returning an empty vector. Other
invalid characters still do.

tests/test_bytevector.cpp

@@ -628,6 +628,18 @@ public:
       CPPUNIT_ASSERT_EQUAL(sempty,ByteVector::fromBase64(invalid));
     }
 
+    // Skip whitespace, as in line wrapped input
+    {
+      CPPUNIT_ASSERT_EQUAL(s1,ByteVector::fromBase64("YW55IGNhcm5h\nbCBwbGVhc3VyZS4="));
+      CPPUNIT_ASSERT_EQUAL(s1,ByteVector::fromBase64("YW55IGNhcm5hbCBw\r\nbGVhc3VyZS4=\r\n"));
+      CPPUNIT_ASSERT_EQUAL(s3,ByteVector::fromBase64(" YW55 IGNh\tcm5hbCBwbGVhc3Vy\n"));
+      CPPUNIT_ASSERT_EQUAL(sempty,ByteVector::fromBase64(" \r\n\t"));
+
+      // Whitespace does not make otherwise invalid input valid
+      CPPUNIT_ASSERT_EQUAL(sempty,ByteVector::fromBase64("YW55\nIGNh-cm5hbCBwbGVhc3VyZS4="));
+      CPPUNIT_ASSERT_EQUAL(sempty,ByteVector::fromBase64("YW55IGNhcm5hbCBwbGVhc3VyZQ=\n"));
+    }
+
   }
 
   void testEmpty()

tests/test_xiphcomment.cpp

@@ -47,6 +47,7 @@ class TestXiphComment : public CppUnit::TestFixture
   CPPUNIT_TEST(testClearComment);
   CPPUNIT_TEST(testRemoveFields);
   CPPUNIT_TEST(testPicture);
+  CPPUNIT_TEST(testWrappedPicture);
   CPPUNIT_TEST(testLowercaseFields);
   CPPUNIT_TEST_SUITE_END();
 
@@ -193,6 +194,43 @@ public:
     }
   }
 
+  void testWrappedPicture()
+  {
+    ScopedFileCopy copy("empty", ".ogg");
+    string newname = copy.fileName();
+
+    FLAC::Picture picture;
+    picture.setType(FLAC::Picture::FrontCover);
+    picture.setMimeType("image/jpeg");
+    picture.setData(ByteVector(200, 'x'));
+
+    // Base64 with a line break every 76 characters, as MIME style encoders write it.
+    const ByteVector base64 = picture.render().toBase64();
+    ByteVector wrapped;
+    for(unsigned int i = 0; i < base64.size(); i += 76) {
+      wrapped.append(base64.mid(i, 76));
+      wrapped.append('\n');
+    }
+
+    {
+      Vorbis::File f(newname.c_str());
+      f.tag()->addField("METADATA_BLOCK_PICTURE", String(wrapped, String::Latin1));
+      f.save();
+    }
+    {
+      Vorbis::File f(newname.c_str());
+      CPPUNIT_ASSERT_EQUAL(1U, f.tag()->pictureList().size());
+      CPPUNIT_ASSERT_EQUAL(ByteVector(200, 'x'), f.tag()->pictureList().front()->data());
+      f.tag()->setTitle("Title");
+      f.save();
+    }
+    {
+      Vorbis::File f(newname.c_str());
+      CPPUNIT_ASSERT_EQUAL(String("Title"), f.tag()->title());
+      CPPUNIT_ASSERT_EQUAL(1U, f.tag()->pictureList().size());
+    }
+  }
+
   void testLowercaseFields()
   {
     const ScopedFileCopy copy("lowercase-fields", ".ogg");