Create long file path before passing to mkdirp (#238)

* Create long file path before passing to mkdirp

* Updated other calls to mkdirp

* Updated mkdirp method to handle both long path and without long path strings

preview/MsixCore/msixmgr/Extractor.cpp

@@ -19,8 +19,8 @@ const PCWSTR Extractor::HandlerName = L"Extractor";
 HRESULT Extractor::GetOutputStream(LPCWSTR path, LPCWSTR fileName, IStream** stream)
 {
     std::wstring fullFileName = path + std::wstring(L"\\") + fileName;
-    RETURN_IF_FAILED(HRESULT_FROM_WIN32(mkdirp(fullFileName)));
     std::wstring longFileName = std::wstring(L"\\\\?\\") + fullFileName;
+    RETURN_IF_FAILED(HRESULT_FROM_WIN32(mkdirp(longFileName)));
     RETURN_IF_FAILED(CreateStreamOnFileUTF16(longFileName.c_str(), false, stream));
     return S_OK;
 }

preview/MsixCore/msixmgr/PopulatePackageInfo.cpp

@@ -37,7 +37,8 @@ HRESULT PopulatePackageInfo::GetPackageInfoFromManifest(const std::wstring & dir
     // On non-Win32 platforms CoCreateAppxFactory will return 0x80070032 (e.g. HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED))
     // So on all platforms, it's always safe to call CoCreateAppxFactoryWithHeap, just be sure to bring your own heap!
     ComPtr<IStream> inputStream;
-    RETURN_IF_FAILED(CreateStreamOnFileUTF16(manifestPath.c_str(), /*forRead*/ true, &inputStream));
+    std::wstring longManifestPath = std::wstring(L"\\\\?\\") + manifestPath;
+    RETURN_IF_FAILED(CreateStreamOnFileUTF16(longManifestPath.c_str(), /*forRead*/ true, &inputStream));
 
     // Create a new package reader using the factory.
     ComPtr<IAppxFactory> appxFactory;

preview/MsixCore/msixmgrLib/GeneralUtil.cpp

@@ -246,7 +246,16 @@ namespace MsixCoreLib
     int mkdirp(std::wstring& utf16Path)
     {
         replace(utf16Path, L'/', L'\\');
-        for (std::size_t i = 3; i < utf16Path.size(); i++) // 3 skips past c:
+        std::size_t startIndex = 0;
+        if (utf16Path.find(L"\\\\?\\") != std::wstring::npos)
+        {
+            startIndex = 7; // 7 skips past \\?\ for handling long file path and c:
+        }
+        else
+        {
+            startIndex = 3; // 3 skips past c:
+        }
+        for (std::size_t i = startIndex; i < utf16Path.size(); i++)
         {
             if (utf16Path[i] == L'\0')
             {