Fix compile error due to incomplete MediaFileInfo

abstractattachment.cpp

@@ -112,6 +112,16 @@ FileDataBlock::FileDataBlock(const string &path, Diagnostics &diag)
     m_stream = [this]() -> std::istream & { return this->m_fileInfo->stream(); };
 }
 
+/*!
+ * \brief Destroys the FileDataBlock.
+ * \remarks This method is needed although it is empty. Otherwise the default d'tor would be
+ *          inlined where FileDataBlock is used creating a dependency to MediaFileInfo which
+ *          therefore couldn't be opaque anymore.
+ */
+FileDataBlock::~FileDataBlock()
+{
+}
+
 /*!
  * \class TagParser::AbstractAttachment
  * \brief The AbstractAttachment class parses and stores attachment information.

abstractattachment.h

@@ -90,6 +90,7 @@ inline void StreamDataBlock::discardBuffer()
 class TAG_PARSER_EXPORT FileDataBlock : public StreamDataBlock {
 public:
     FileDataBlock(const std::string &path, Diagnostics &diag);
+    ~FileDataBlock();
     const MediaFileInfo *fileInfo() const;
 
 private: