Fix a potential race condition

Common/Net/HTTPRequest.h

@@ -46,6 +46,7 @@ public:
 		if (callback_) {
 			callback_(*this);
 		}
+		hasRunCallback_ = true;
 	}
 
 	virtual void Start() = 0;
@@ -54,6 +55,8 @@ public:
 	virtual bool Done() = 0;
 	virtual bool Failed() const = 0;
 
+	virtual bool HasRunCallback() { return Done() && hasRunCallback_; }
+
 	// Returns 1.0 when done. That one value can be compared exactly - or just use Done().
 	float Progress() const { return progress_.progress; }
 	float SpeedKBps() const { return progress_.kBps; }
@@ -87,6 +90,7 @@ protected:
 	Buffer buffer_;
 	bool cancelled_ = false;
 	int resultCode_ = 0;
+	bool hasRunCallback_ = false;
 	std::vector<std::string> responseHeaders_;
 
 	net::RequestProgress progress_;

Core/HLE/sceNetAdhoc.cpp

@@ -213,7 +213,8 @@ void AdhocLoadServerList(bool sync) {
 			do {
 				sleep_ms(10, "waiting-for-adhoc-server-list");
 				g_DownloadManager.Update();
-			} while (!dl->Done());
+			} while (!dl->HasRunCallback());
+			dl.reset();
 		}
 		g_serverListLoaded = true;
 	} else if (!g_Config.sAdhocServerListUrl.empty()) {