- ZipArchive namespace for operations with zip archives, located in CZipLoader.h/cpp.

- new fields in mod format, for use with mod manager (check config/shemas/mod.json for details)
- removed some 0.92 compatibility from mods loading
- several compile fixes

lib/filesystem/CZipLoader.cpp

@@ -2,6 +2,8 @@
 #include "../../Global.h"
 #include "CZipLoader.h"
 
+#include "../ScopeGuard.h"
+
 /*
  * CZipLoader.cpp, part of VCMI engine
  *
@@ -99,4 +101,102 @@ std::unordered_set<ResourceID> CZipLoader::getFilteredFiles(std::function<bool(c
 			foundID.insert(file.first);
 	}
 	return foundID;
-}
+}
+
+/// extracts currently selected file from zip into stream "where"
+static bool extractCurrent(unzFile file, std::ostream & where)
+{
+	std::array<char, 8 * 1024> buffer;
+
+	unzOpenCurrentFile(file);
+
+	while (1)
+	{
+		int readSize = unzReadCurrentFile(file, buffer.data(), buffer.size());
+
+		if (readSize < 0) // error
+			break;
+
+		if (readSize == 0) // end-of-file. Also performs CRC check
+			return unzCloseCurrentFile(file) == UNZ_OK;
+
+		if (readSize > 0) // successfull read
+		{
+			where.write(buffer.data(), readSize);
+			if (!where.good())
+				break;
+		}
+	}
+
+	// extraction failed. Close file and exit
+	unzCloseCurrentFile(file);
+	return false;
+}
+
+std::vector<std::string> ZipArchive::listFiles(std::string filename)
+{
+	std::vector<std::string> ret;
+
+	unzFile file = unzOpen(filename.c_str());
+
+	if (unzGoToFirstFile(file) == UNZ_OK)
+	{
+		do
+		{
+			unz_file_info info;
+			std::vector<char> filename;
+
+			unzGetCurrentFileInfo (file, &info, nullptr, 0, nullptr, 0, nullptr, 0);
+
+			filename.resize(info.size_filename);
+			// Get name of current file. Contrary to docs "info" parameter can't be null
+			unzGetCurrentFileInfo (file, &info, filename.data(), filename.size(), nullptr, 0, nullptr, 0);
+
+			ret.push_back(std::string(filename.data(), filename.size()));
+		}
+		while (unzGoToNextFile(file) == UNZ_OK);
+	}
+	unzClose(file);
+
+	return ret;
+}
+
+bool ZipArchive::extract(std::string from, std::string where)
+{
+	// Note: may not be fast enough for large archives (should NOT happen with mods)
+	// because locating each file by name may be slow. Unlikely slower than decompression though
+	return extract(from, where, listFiles(from));
+}
+
+bool ZipArchive::extract(std::string from, std::string where, std::vector<std::string> what)
+{
+	unzFile archive = unzOpen(from.c_str());
+
+	auto onExit = vstd::makeScopeGuard([&]()
+	{
+		unzClose(archive);
+	});
+
+	for (std::string & file : what)
+	{
+		if (unzLocateFile(archive, file.c_str(), 1) != UNZ_OK)
+			return false;
+
+		std::string fullName = where + '/' + file;
+		std::string fullPath = fullName.substr(0, fullName.find_last_of("/"));
+
+		boost::filesystem::create_directories(fullPath);
+		// directory. No file to extract
+		// TODO: better way to detect directory? Probably check return value of unzOpenCurrentFile?
+		if (boost::algorithm::ends_with(file, "/"))
+			continue;
+
+		std::ofstream destFile(fullName);
+		if (!destFile.good())
+			return false;
+
+		if (!extractCurrent(archive, destFile))
+			return false;
+	}
+	return true;
+}