Update: Get nightly (prerelease) builds from Github

We are now deploying official builds from master to Github releases page
(as Prerelease).
So we should get these build from there.

This is also related to AppVeyor's rather tight download limits that
make it quite challenge to obtain nightly builds.

Author: ge0rdi

Src/Lib/DownloadHelper.cpp

@@ -344,7 +344,7 @@ static DWORD WINAPI ThreadVersionCheck( void *param )
 	VersionData data;
 
 	{
-		auto load = params.nightly ? data.LoadNightly() : data.Load();
+		auto load = data.Load(!params.nightly);
 
 #ifdef UPDATE_LOG
 		LogToFile(UPDATE_LOG, L"Load result: %d", load);
@@ -765,20 +765,38 @@ std::vector<char> DownloadUrl(const wchar_t* url)
 
 using namespace nlohmann;
 
-VersionData::TLoadResult VersionData::Load()
+VersionData::TLoadResult VersionData::Load(bool official)
 {
 	Clear();
 
-	auto buf = DownloadUrl(L"https://api.github.com/repos/Open-Shell/Open-Shell-Menu/releases/latest");
+	std::wstring baseUrl = L"https://api.github.com/repos/Open-Shell/Open-Shell-Menu/releases";
+	if (official)
+		baseUrl += L"/latest";
+
+	auto buf = DownloadUrl(baseUrl.c_str());
 	if (buf.empty())
 		return LOAD_ERROR;
 
 	try
 	{
-		auto data = json::parse(buf.begin(), buf.end());
+		auto jsonData = json::parse(buf.begin(), buf.end());
+		auto& data = jsonData;
+
+		if (official)
+		{
+			// skip prerelease versions (just in case)
+			if (data["prerelease"].get<bool>())
+				return LOAD_BAD_VERSION;
+		}
+		else
+		{
+			// we've got list of versions (release and pre-release)
+			// lets pick first one (that should be the latest one)
+			data = jsonData[0];
+		}
 
-		// skip prerelease versions
-		if (data["prerelease"].get<bool>())
+		// make sure we didn't get draft release (for whatever reason)
+		if (data["draft"].get<bool>())
 			return LOAD_BAD_VERSION;
 
 		// get version from tag name

Src/Lib/DownloadHelper.h

@@ -59,7 +59,7 @@ struct VersionData
 		LOAD_BAD_FILE, // the file is corrupted
 	};
 
-	TLoadResult Load();
+	TLoadResult Load(bool official);
 	TLoadResult LoadNightly();
 	TLoadResult Load( const wchar_t *fname, bool bLoadFlags );
 private: