net: initialize socket to avoid closing random fd's

Github-Pull: #12326
Rebased-From: 96dbd381cf0ded169406bab3b1ba911a13d563c5
Tree-SHA512: 8b4a09974060e6d0992e7b9ec06c5de3ad2daf970c4484077fda803f37d3ed874dcb6fec226107b2aa0fa64cfe4116604ca4f90599430fcc622bbb805be55e1b

src/net.cpp

@@ -410,7 +410,7 @@ CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCo
 
     // Connect
     bool connected = false;
-    SOCKET hSocket;
+    SOCKET hSocket = INVALID_SOCKET;
     proxyType proxy;
     if (addrConnect.IsValid()) {
         bool proxyConnectionFailed = false;

src/netbase.cpp

@@ -682,6 +682,9 @@ bool CloseSocket(SOCKET& hSocket)
 #else
     int ret = close(hSocket);
 #endif
+    if (ret) {
+        LogPrintf("Socket close failed: %d. Error: %s\n", hSocket, NetworkErrorString(WSAGetLastError()));
+    }
     hSocket = INVALID_SOCKET;
     return ret != SOCKET_ERROR;
 }