Fixed bug #38469 (unexpected creation of cycle, json tests failed, leaks memory)

NEWS

@@ -91,6 +91,7 @@ PHP                                                                        NEWS
   (Lars W)
 - Fixed bug #39397 (invalid statement handle in Unknown on line 0). (Lars W)
 - Fixed bug #39056 (Interbase NUMERIC data type error). (Lars W)
+- Fixed bug #38468 (Unexpected creation of cycle). (Dmitry)
 - Fixed bug #37911 (preg_replace_callback() ignores named groups). (Nuno)
 - Fixed bug #36128 (Interbase PDO - timestamp columns return NULL). (Lars W)
 - Fixed bug #35386 (firebird: first row is null). (Lars W)

Zend/tests/bug38469.phpt

@@ -0,0 +1,28 @@
+--TEST--
+Bug #38469 Unexpected creation of cycle
+--FILE--
+<?php
+$a = array();
+$a[0] = $a;
+var_dump($a);
+$b = array(array());
+$b[0][0] = $b;
+var_dump($b);
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  array(0) {
+  }
+}
+array(1) {
+  [0]=>
+  array(1) {
+    [0]=>
+    array(1) {
+      [0]=>
+      array(0) {
+      }
+    }
+  }
+}

Zend/zend_compile.c

@@ -546,8 +546,39 @@ static zend_bool opline_is_fetch_this(zend_op *opline TSRMLS_DC)
 
 void zend_do_assign(znode *result, znode *variable, znode *value TSRMLS_DC)
 {
-	int last_op_number = get_next_op_number(CG(active_op_array));
-	zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);
+	int last_op_number;
+	zend_op *opline;
+
+	if (value->op_type == IS_CV) {
+		zend_llist *fetch_list_ptr;
+
+		zend_stack_top(&CG(bp_stack), (void **) &fetch_list_ptr);
+		if (fetch_list_ptr && fetch_list_ptr->head) {
+			opline = (zend_op *)fetch_list_ptr->head->data;
+
+			if (opline->opcode == ZEND_FETCH_DIM_W &&
+			    opline->op1.op_type == IS_CV &&
+			    opline->op1.u.var == value->u.var) {
+
+				opline = get_next_op(CG(active_op_array) TSRMLS_CC);
+				opline->opcode = ZEND_FETCH_R;
+				opline->result.op_type = IS_VAR;
+				opline->result.u.EA.type = 0;
+				opline->result.u.var = get_temporary_variable(CG(active_op_array));
+				opline->op1.op_type = IS_CONST;
+				ZVAL_STRINGL(&opline->op1.u.constant,
+					CG(active_op_array)->vars[value->u.var].name, 
+					CG(active_op_array)->vars[value->u.var].name_len, 1);
+				SET_UNUSED(opline->op2);
+				value = &opline->result;
+			}
+		}
+	}
+
+	zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC);
+
+	last_op_number = get_next_op_number(CG(active_op_array));
+	opline = get_next_op(CG(active_op_array) TSRMLS_CC);
 
 	if (variable->op_type == IS_VAR) {
 		int n = 0;
@@ -3840,8 +3871,6 @@ void zend_do_list_end(znode *result, znode *expr TSRMLS_DC)
 	zend_llist_element *dimension;
 	zend_op *opline;
 	znode last_container;
-	int last_op_number;
-	zend_op *last_op;
 
 	le = CG(list_llist).head;
 	while (le) {
@@ -3881,9 +3910,6 @@ void zend_do_list_end(znode *result, znode *expr TSRMLS_DC)
 		}
 		((list_llist_element *) le->data)->value = last_container;
 		zend_llist_destroy(&((list_llist_element *) le->data)->dimensions);
-		zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC);
-		last_op_number = get_next_op_number(CG(active_op_array))-1;
-		last_op = &CG(active_op_array)->opcodes[last_op_number];
 		zend_do_assign(result, &((list_llist_element *) le->data)->var, &((list_llist_element *) le->data)->value TSRMLS_CC);
 		zend_do_free(result TSRMLS_CC);
 		le = le->next;
@@ -4244,8 +4270,8 @@ void zend_do_foreach_cont(znode *foreach_token, znode *open_brackets_token, znod
 
 	value_node = opline->result;
 
-	zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC);
 	if (assign_by_ref) {
+		zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC);
 		/* Mark FE_FETCH as IS_VAR as it holds the data directly as a value */
 		zend_do_assign_ref(NULL, value, &value_node TSRMLS_CC);
 	} else {
@@ -4256,7 +4282,6 @@ void zend_do_foreach_cont(znode *foreach_token, znode *open_brackets_token, znod
 	if (key->op_type != IS_UNUSED) {
 		znode key_node;
 
-		zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC);
 		opline = &CG(active_op_array)->opcodes[as_token->u.opline_num+1];
 		opline->result.op_type = IS_TMP_VAR;
 		opline->result.u.EA.type = 0;

Zend/zend_language_parser.y

@@ -560,7 +560,7 @@ non_empty_for_expr:
 
 expr_without_variable:
 		T_LIST '(' { zend_do_list_init(TSRMLS_C); } assignment_list ')' '=' expr { zend_do_list_end(&$$, &$7 TSRMLS_CC); }
-	|	variable '=' expr		{ zend_check_writable_variable(&$1); zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC); zend_do_assign(&$$, &$1, &$3 TSRMLS_CC); }
+	|	variable '=' expr		{ zend_check_writable_variable(&$1); zend_do_assign(&$$, &$1, &$3 TSRMLS_CC); }
 	|	variable '=' '&' variable { zend_check_writable_variable(&$1); zend_do_end_variable_parse(BP_VAR_W, 1 TSRMLS_CC); zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC); zend_do_assign_ref(&$$, &$1, &$4 TSRMLS_CC); }
 	|	variable '=' '&' T_NEW class_name_reference { zend_error(E_STRICT, "Assigning the return value of new by reference is deprecated");  zend_check_writable_variable(&$1); zend_do_extended_fcall_begin(TSRMLS_C); zend_do_begin_new_object(&$4, &$5 TSRMLS_CC); } ctor_arguments { zend_do_end_new_object(&$3, &$4, &$7 TSRMLS_CC); zend_do_extended_fcall_end(TSRMLS_C); zend_do_end_variable_parse(BP_VAR_W, 0 TSRMLS_CC); zend_do_assign_ref(&$$, &$1, &$3 TSRMLS_CC); }
 	|	T_NEW class_name_reference { zend_do_extended_fcall_begin(TSRMLS_C); zend_do_begin_new_object(&$1, &$2 TSRMLS_CC); } ctor_arguments { zend_do_end_new_object(&$$, &$1, &$4 TSRMLS_CC); zend_do_extended_fcall_end(TSRMLS_C);}