empty.diff

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index c3c35eb..b1feb7a 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -6089,7 +6089,19 @@ void zend_do_isset_or_isempty(int type, znode *result, znode *variable TSRMLS_DC
 
 	zend_do_end_variable_parse(variable, BP_VAR_IS, 0 TSRMLS_CC);
 
-	zend_check_writable_variable(variable);
+	if (type == ZEND_ISEMPTY) {
+		// if the empty() argument is the result of a function call we already
+		// know that the variable exists, so we can just convert the empty()
+		// call to a boolean not
+		if (zend_is_function_or_method_call(variable)) {
+			zend_do_unary_op(ZEND_BOOL_NOT, result, variable TSRMLS_CC);
+			return;
+		}
+	} else {
+		// it doesn't make sense to pass the result of a function call to
+		// isset() as it will always be bool(true). Thus disallow them here
+		zend_check_writable_variable(variable);
+	}
 
 	if (variable->op_type == IS_CV) {
 		last_op = get_next_op(CG(active_op_array) TSRMLS_CC);
diff --git a/Zend/zend_language_parser.y b/Zend/zend_language_parser.y
index d0730b7..1a9d212 100644
--- a/Zend/zend_language_parser.y
+++ b/Zend/zend_language_parser.y
@@ -1149,6 +1149,7 @@ encaps_var_offset:
 internal_functions_in_yacc:
 		T_ISSET '(' isset_variables ')' { $$ = $3; }
 	|	T_EMPTY '(' variable ')'	{ zend_do_isset_or_isempty(ZEND_ISEMPTY, &$$, &$3 TSRMLS_CC); }
+	|	T_EMPTY '(' expr_without_variable ')' { zend_do_unary_op(ZEND_BOOL_NOT, &$$, &$3 TSRMLS_CC); }
 	|	T_INCLUDE expr 			{ zend_do_include_or_eval(ZEND_INCLUDE, &$$, &$2 TSRMLS_CC); }
 	|	T_INCLUDE_ONCE expr 	{ zend_do_include_or_eval(ZEND_INCLUDE_ONCE, &$$, &$2 TSRMLS_CC); }
 	|	T_EVAL '(' expr ')' 	{ zend_do_include_or_eval(ZEND_EVAL, &$$, &$3 TSRMLS_CC); }

Please patch isset as well ;)