work out how to handle worksheet rels during streaming parsing

include/xlnt/workbook/streaming_workbook_reader.hpp

@@ -115,6 +115,7 @@ public:
     void open(std::istream &stream);
 
 private:
+    std::vector<std::string> worksheet_queue_;
     std::unique_ptr<detail::xlsx_consumer> consumer_;
     std::unique_ptr<workbook> workbook_;
 };

source/detail/cryptography/xlsx_crypto_consumer.cpp

@@ -108,7 +108,7 @@ std::vector<std::uint8_t> decrypt_xlsx_agile(
         ++segment;
     }
 
-    decrypted_package.resize(total_size);
+    decrypted_package.resize(static_cast<std::size_t>(total_size));
 
     return decrypted_package;
 }
@@ -153,7 +153,8 @@ encryption_info::standard_encryption_info read_standard_encryption_info(std::ist
         throw xlnt::exception("invalid header");
     }
 
-    const auto csp_name_length = (header_length - (info_stream.tellg() - index_at_start)) / 2;
+    const auto csp_name_length = static_cast<std::size_t>((header_length 
+        - (info_stream.tellg() - index_at_start)) / 2);
     auto csp_name = xlnt::detail::read_string<char16_t>(info_stream, csp_name_length);
     csp_name.pop_back(); // remove extraneous trailing null
     if (csp_name != u"Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)"

source/detail/serialization/xlsx_consumer.hpp

@@ -82,16 +82,6 @@ private:
     /// </summary>
     cell read_cell();
 
-    /// <summary>
-    /// Ends reading of the current worksheet in the workbook and optionally
-    /// returns a worksheet object corresponding to the worksheet with the title
-    /// returned by begin_worksheet(). An exception will be thrown if this is 
-    /// not open as a streaming consumer.
-    /// </summary>
-    worksheet end_worksheet();
-
-    bool has_worksheet();
-
 	/// <summary>
 	/// Read all the files needed from the XLSX archive and initialize all of
 	/// the data in the workbook to match.
@@ -198,27 +188,27 @@ private:
 	/// <summary>
 	/// xl/sheets/*.xml
 	/// </summary>
-	void read_chartsheet(const std::string &title);
+	void read_chartsheet(const std::string &rel_id);
 
 	/// <summary>
 	/// xl/sheets/*.xml
 	/// </summary>
-	void read_dialogsheet(const std::string &title);
+	void read_dialogsheet(const std::string &rel_id);
 
 	/// <summary>
 	/// xl/sheets/*.xml
 	/// </summary>
-	void read_worksheet(const std::string &title);
+	void read_worksheet(const std::string &rel_id);
 
     /// <summary>
     /// xl/sheets/*.xml
     /// </summary>
-    std::string read_worksheet_begin();
+    std::string read_worksheet_begin(const std::string &rel_id);
 
     /// <summary>
     /// xl/sheets/*.xml
     /// </summary>
-    void read_worksheet_end();
+    worksheet read_worksheet_end(const std::string &rel_id);
 
 	// Sheet Relationship Target Parts
 
@@ -411,13 +401,9 @@ private:
 
     bool preserve_space_ = false;
 
-    std::vector<relationship> worksheet_queue_;
-
     detail::cell_impl *stream_cell_;
 
     detail::worksheet_impl *stream_worksheet_;
-
-    bool in_sheet_data_;
 };
 
 } // namespace detail

source/workbook/streaming_workbook_reader.cpp

@@ -103,17 +103,20 @@ cell streaming_workbook_reader::read_cell()
 
 bool streaming_workbook_reader::has_worksheet()
 {
-    return consumer_->has_worksheet();
+    return !worksheet_queue_.empty();
 }
 
 std::string streaming_workbook_reader::begin_worksheet()
 {
-    return consumer_->read_worksheet_begin();
+    auto next_worksheet_rel = worksheet_queue_.back();
+    return consumer_->read_worksheet_begin(next_worksheet_rel);
 }
 
 worksheet streaming_workbook_reader::end_worksheet()
 {
-    return consumer_->end_worksheet();
+    auto next_worksheet_rel = worksheet_queue_.back();
+    worksheet_queue_.pop_back();
+    return consumer_->read_worksheet_end(next_worksheet_rel);
 }
 
 void streaming_workbook_reader::open(const std::vector<std::uint8_t> &data)