wininet: HTTP_Connect should fail if a NULL or empty hostname is passed in.

dlls/wininet/http.c

@@ -2795,6 +2795,12 @@ HINTERNET HTTP_Connect(LPWININETAPPINFOW hIC, LPCWSTR lpszServerName,
 
     TRACE("-->\n");
 
+    if (!lpszServerName || !lpszServerName[0])
+    {
+        INTERNET_SetLastError(ERROR_INVALID_PARAMETER);
+        goto lerror;
+    }
+
     assert( hIC->hdr.htype == WH_HINIT );
 
     lpwhs = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(WININETHTTPSESSIONW));

dlls/wininet/tests/http.c

@@ -929,9 +929,19 @@ static void InternetOpenRequest_test(void)
     session = InternetOpenA("Wine Regression Test", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
     ok(session != NULL ,"Unable to open Internet session\n");
 
+    connect = InternetConnectA(session, NULL, INTERNET_DEFAULT_HTTP_PORT, NULL, NULL,
+                              INTERNET_SERVICE_HTTP, 0, 0);
+    ok(connect == NULL, "InternetConnectA should have failed\n");
+    ok(GetLastError() == ERROR_INVALID_PARAMETER, "InternetConnectA with NULL server named should have failed with ERROR_INVALID_PARAMETER instead of %d\n", GetLastError());
+
+    connect = InternetConnectA(session, "", INTERNET_DEFAULT_HTTP_PORT, NULL, NULL,
+                              INTERNET_SERVICE_HTTP, 0, 0);
+    ok(connect == NULL, "InternetConnectA should have failed\n");
+    ok(GetLastError() == ERROR_INVALID_PARAMETER, "InternetConnectA with blank server named should have failed with ERROR_INVALID_PARAMETER instead of %d\n", GetLastError());
+
     connect = InternetConnectA(session, "winehq.org", INTERNET_DEFAULT_HTTP_PORT, NULL, NULL,
                               INTERNET_SERVICE_HTTP, 0, 0);
-    ok(connect != NULL, "Unable to connect to http://winehq.org\n");
+    ok(connect != NULL, "Unable to connect to http://winehq.org with error %d\n", GetLastError());
 
     request = HttpOpenRequestA(connect, NULL, "/", NULL, NULL, types, INTERNET_FLAG_NO_CACHE_WRITE, 0);
     if (!request && GetLastError() == ERROR_INTERNET_NAME_NOT_RESOLVED)