Description:
------------
There are several possible mistakes in "standard" PHP extension code.

1. flock_compat.c, php_flock function:

HANDLE hdl = (HANDLE) _get_osfhandle(fd);
DWORD low = 1, high = 0;
OVERLAPPED offset =
{0, 0, 0, 0, NULL};
DWORD err;

if (hdl < 0) { // <-- Comparing pointer < 0. Pointer value can't be less than zero. Correct comparison: hdl == INVALID_HANDLE_VALUE
	_set_errno(EBADF);
	return -1;              /* error in file descriptor */
}




2. filters.c, php_conv_qprint_encode_convert function, possible zero pointer dereferencing:

c = NEXT_CHAR(ps, icnt, lb_ptr, lb_cnt, inst->lbchars); // <-- Access to inst->lbchars[lb_ptr] inside the macro

if (!(opts & PHP_CONV_QPRINT_OPT_BINARY) &&
	(trail_ws == 0) &&
	(c == '\t' || c == ' ')) {
	if (line_ccnt < 2 && inst->lbchars != NULL) { // <-- Later check if inst->lbchars is not NULL



3. http_fopen_wrapper.c, php_stream_url_wrap_http_ex function, possible zero pointer dereferencing:

ua = emalloc(ua_len + 1);
if ((ua_len = slprintf(ua, ua_len, _UA_HEADER, ua_str)) > 0) { // <-- Access to ua
	ua[ua_len] = 0;
	php_stream_write(stream, ua, ua_len);
} else {
	php_error_docref(NULL, E_WARNING, "Cannot construct User-agent header");
}

if (ua) { // <-- Later check if ua is not NULL
	efree(ua);
}




4. uuencode.c, php_uudecode function:

assert(p >= ZSTR_VAL(dest));
if ((len = total_len > (size_t)(p - ZSTR_VAL(dest)))) { // <-- Possible absence of brackets: this expression should be if(((len = total_len) > ...))




5. var.c, php_var_serialize_intern function:

zend_class_entry *ce = Z_OBJCE_P(struc);

if (ce->serialize != NULL) { // <-- Access to ce->serialize

...

if (ce && ce != PHP_IC_ENTRY && zend_hash_str_exists(&ce->function_table, "__sleep", sizeof("__sleep")-1)) { // <-- Later check if ce is not NULL





6. var.c, php_var_serialize_intern function (again):

if (incomplete_class && strcmp(ZSTR_VAL(key), MAGIC_MEMBER) == 0) { // <-- Access to key->val
	continue;
}

if (!key) { // <-- Later check if key is not NULL
	php_var_serialize_long(buf, index);
} else {
	php_var_serialize_string(buf, ZSTR_VAL(key), ZSTR_LEN(key));
}