wininet: Avoid a crash on an invalid handle in InternetQueryOption.

dlls/wininet/internet.c

@@ -1904,7 +1904,7 @@ static BOOL INET_QueryOptionHelper(BOOL bIsUnicode, HINTERNET hInternet, DWORD d
 
             TRACE("INTERNET_OPTION_USER_AGENT\n");
 
-            if (lpwhh->htype != INTERNET_HANDLE_TYPE_INTERNET)
+            if (!lpwhh || lpwhh->htype != INTERNET_HANDLE_TYPE_INTERNET)
             {
                 INTERNET_SetLastError(ERROR_INTERNET_INCORRECT_HANDLE_TYPE);
                 return FALSE;

dlls/wininet/tests/internet.c

@@ -150,6 +150,12 @@ static void test_InternetQueryOptionA(void)
   ok((hinet != 0x0),"InternetOpen Failed\n");
 
   SetLastError(0xdeadbeef);
+  retval=InternetQueryOptionA(NULL,INTERNET_OPTION_USER_AGENT,NULL,&len);
+  err=GetLastError();
+  ok(retval == 0,"Got wrong return value %d\n",retval);
+  ok(err == ERROR_INTERNET_INCORRECT_HANDLE_TYPE, "Got wrong error code%d\n",err);
+
+  SetLastError(0xdeadbeef);
   len=strlen(useragent)+1;
   retval=InternetQueryOptionA(hinet,INTERNET_OPTION_USER_AGENT,NULL,&len);
   err=GetLastError();