The comment in imageFile.hpp around line 206 in imageFile.hpp reads:

// Ex. Container offset (ATTRIBUTE_OFFSET) 0x33562 would be represented as 0x22
// (kind = 4, length = 3), 0x03, 0x35, 0x62.

This assumes that ATTRIBUTE_OFFSET gets int value 4, while it currently has this enum definition:

    enum {
        ATTRIBUTE_END, // End of attribute stream marker
        ATTRIBUTE_MODULE, // String table offset of module name
        ATTRIBUTE_PARENT, // String table offset of resource path parent
        ATTRIBUTE_BASE, // String table offset of resource path base
        ATTRIBUTE_EXTENSION, // String table offset of resource path extension
        ATTRIBUTE_OFFSET, // Container byte offset of resource
        ATTRIBUTE_COMPRESSED, // In image byte size of the compressed resource
        ATTRIBUTE_UNCOMPRESSED, // In memory byte size of the uncompressed resource
        ATTRIBUTE_COUNT // Number of attribute kinds
    };

So ATTRIBUTE_OFFSET is actually int value 5, not 4 as alluded to in the comment. ATTRIBUTE_EXTENSION is int value 4.

Also the ATTRIBUTE_END notes seem confusing. What's meant there, I think, is that lower 3 bits might be non-zero for an ATTRIBUTE_END byte, thus checking for a zero byte is not sufficient.