From: Nikita Popov <nikita.ppv@gmail.com>
Date: Mon, 25 Dec 2017 20:19:45 +0000 (+0100)
Subject: Remove unnecessary readobj==writeobj checks
X-Git-Tag: php-7.3.0alpha1~740
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=2667ddc46d7cf2ca268ecb5d1599ad4afaf19c89;p=php

Remove unnecessary readobj==writeobj checks

This can no longer be the case since PHP 7. The writeobj must
always point to a different zval.
---

diff --git a/Zend/zend_object_handlers.c b/Zend/zend_object_handlers.c
index 51ec12352f..86d812dbea 100644
--- a/Zend/zend_object_handlers.c
+++ b/Zend/zend_object_handlers.c
@@ -1675,16 +1675,10 @@ ZEND_API int zend_std_cast_object_tostring(zval *readobj, zval *writeobj, int ty
 					return FAILURE;
 				}
 				if (EXPECTED(Z_TYPE(retval) == IS_STRING)) {
-					if (readobj == writeobj) {
-						zval_ptr_dtor(readobj);
-					}
 					ZVAL_COPY_VALUE(writeobj, &retval);
 					return SUCCESS;
 				} else {
 					zval_ptr_dtor(&retval);
-					if (readobj == writeobj) {
-						zval_ptr_dtor(readobj);
-					}
 					ZVAL_EMPTY_STRING(writeobj);
 					zend_error(E_RECOVERABLE_ERROR, "Method %s::__toString() must return a string value", ZSTR_VAL(ce->name));
 					return SUCCESS;
@@ -1692,22 +1686,16 @@ ZEND_API int zend_std_cast_object_tostring(zval *readobj, zval *writeobj, int ty
 			}
 			return FAILURE;
 		case _IS_BOOL:
-			ZVAL_BOOL(writeobj, 1);
+			ZVAL_TRUE(writeobj);
 			return SUCCESS;
 		case IS_LONG:
 			ce = Z_OBJCE_P(readobj);
 			zend_error(E_NOTICE, "Object of class %s could not be converted to int", ZSTR_VAL(ce->name));
-			if (readobj == writeobj) {
-				zval_dtor(readobj);
-			}
 			ZVAL_LONG(writeobj, 1);
 			return SUCCESS;
 		case IS_DOUBLE:
 			ce = Z_OBJCE_P(readobj);
 			zend_error(E_NOTICE, "Object of class %s could not be converted to float", ZSTR_VAL(ce->name));
-			if (readobj == writeobj) {
-				zval_dtor(readobj);
-			}
 			ZVAL_DOUBLE(writeobj, 1);
 			return SUCCESS;
 		default:
diff --git a/Zend/zend_object_handlers.h b/Zend/zend_object_handlers.h
index 29494d9006..465f6a426c 100644
--- a/Zend/zend_object_handlers.h
+++ b/Zend/zend_object_handlers.h
@@ -115,7 +115,8 @@ typedef zend_string *(*zend_object_get_class_name_t)(const zend_object *object);
 typedef int (*zend_object_compare_t)(zval *object1, zval *object2);
 typedef int (*zend_object_compare_zvals_t)(zval *resul, zval *op1, zval *op2);
 
-/* Cast an object to some other type
+/* Cast an object to some other type.
+ * readobj and retval must point to distinct zvals.
  */
 typedef int (*zend_object_cast_t)(zval *readobj, zval *retval, int type);
 
diff --git a/ext/simplexml/simplexml.c b/ext/simplexml/simplexml.c
index f30d1fd041..66ac14ad88 100644
--- a/ext/simplexml/simplexml.c
+++ b/ext/simplexml/simplexml.c
@@ -1904,10 +1904,6 @@ static int sxe_object_cast_ex(zval *readobj, zval *writeobj, int type)
 		}
 	}
 
-	if (readobj == writeobj) {
-		zval_ptr_dtor(readobj);
-	}
-
 	rv = cast_object(writeobj, type, (char *)contents);
 
 	if (contents) {
diff --git a/ext/spl/spl_directory.c b/ext/spl/spl_directory.c
index a58d5b3cdf..4a012d74ea 100644
--- a/ext/spl/spl_directory.c
+++ b/ext/spl/spl_directory.c
@@ -1863,37 +1863,16 @@ static int spl_filesystem_object_cast(zval *readobj, zval *writeobj, int type)
 		switch (intern->type) {
 		case SPL_FS_INFO:
 		case SPL_FS_FILE:
-			if (readobj == writeobj) {
-				zval retval;
-				zval *retval_ptr = &retval;
-
-				ZVAL_STRINGL(retval_ptr, intern->file_name, intern->file_name_len);
-				zval_ptr_dtor(readobj);
-				ZVAL_NEW_STR(writeobj, Z_STR_P(retval_ptr));
-			} else {
-				ZVAL_STRINGL(writeobj, intern->file_name, intern->file_name_len);
-			}
+			ZVAL_STRINGL(writeobj, intern->file_name, intern->file_name_len);
 			return SUCCESS;
 		case SPL_FS_DIR:
-			if (readobj == writeobj) {
-				zval retval;
-				zval *retval_ptr = &retval;
-
-				ZVAL_STRING(retval_ptr, intern->u.dir.entry.d_name);
-				zval_ptr_dtor(readobj);
-				ZVAL_NEW_STR(writeobj, Z_STR_P(retval_ptr));
-			} else {
-				ZVAL_STRING(writeobj, intern->u.dir.entry.d_name);
-			}
+			ZVAL_STRING(writeobj, intern->u.dir.entry.d_name);
 			return SUCCESS;
 		}
 	} else if (type == _IS_BOOL) {
 		ZVAL_TRUE(writeobj);
 		return SUCCESS;
 	}
-	if (readobj == writeobj) {
-		zval_ptr_dtor(readobj);
-	}
 	ZVAL_NULL(writeobj);
 	return FAILURE;
 }