- Rename compatiblity mode to zend.ze2_compatibility_mode (it doesn't only affect auto-clone).

- Perform implementation checks even with simple inheritance (off when
  compatibility mode is enabled).
- Restore default arguments in interfaces and handle it correctly.
- Move registration of internal classes later in the startup sequence
  in order to have INI options available.

Zend/zend.c

@@ -73,20 +73,9 @@ static ZEND_INI_MH(OnUpdateErrorReporting)
 }
 
 
-static ZEND_INI_MH(OnUpdateImplicitClone)
-{
-	if (!new_value) {
-		EG(implicit_clone) = 0;
-	} else {
-		EG(implicit_clone) = atoi(new_value) ? 1 : 0;
-	}
-	return SUCCESS;
-}
-
-
 ZEND_INI_BEGIN()
-	ZEND_INI_ENTRY("error_reporting",			NULL,		ZEND_INI_ALL,		OnUpdateErrorReporting)
-	ZEND_INI_ENTRY("zend2.implicit_clone",		NULL,		ZEND_INI_ALL,		OnUpdateImplicitClone)
+	ZEND_INI_ENTRY("error_reporting",				NULL,		ZEND_INI_ALL,		OnUpdateErrorReporting)
+	STD_ZEND_INI_BOOLEAN("zend.ze1_compatibility_mode",	"0",	ZEND_INI_ALL,		OnUpdateBool,	ze1_compatibility_mode,	zend_executor_globals,	executor_globals)
 ZEND_INI_END()
 
 
@@ -643,7 +632,6 @@ int zend_startup(zend_utility_functions *utility_functions, char **extensions, i
 	if (start_builtin_functions) {
 		zend_startup_builtin_functions(TSRMLS_C);
 	}
-	zend_register_default_classes(TSRMLS_C);
 
 	zend_ini_startup(TSRMLS_C);
 

Zend/zend_compile.c

@@ -1136,11 +1136,6 @@ void zend_do_receive_arg(zend_uchar op, znode *var, znode *offset, znode *initia
 	opline->result = *var;
 	opline->op1 = *offset;
 	if (op == ZEND_RECV_INIT) {
-		if ((CG(active_class_entry) && CG(active_class_entry)->ce_flags & ZEND_ACC_INTERFACE)
-			|| CG(active_op_array)->fn_flags & ZEND_ACC_ABSTRACT) {
-			CG(active_op_array)->num_args--; /* invalidate the current arg_info entry */
-			zend_error(E_COMPILE_ERROR, "Abstract methods cannot have default values for arguments");
-		}
 		opline->op2 = *initialization;
 	} else {
 		CG(active_op_array)->required_num_args = CG(active_op_array)->num_args;
@@ -1723,7 +1718,7 @@ static zend_bool zend_do_perform_implementation_check(zend_function *fe)
 	}
 
 	/* check number of arguments */
-	if (proto->common.num_args < fe->common.required_num_args
+	if (proto->common.required_num_args != fe->common.required_num_args
 		|| proto->common.num_args > fe->common.num_args) {
 		return 0;
 	}
@@ -1768,6 +1763,7 @@ static zend_bool do_inherit_method_check(HashTable *child_function_table, zend_f
 	zend_uint child_flags;
 	zend_uint parent_flags = parent->common.fn_flags;
 	zend_function *child;
+	TSRMLS_FETCH();
 
 	if (zend_hash_quick_find(child_function_table, hash_key->arKey, hash_key->nKeyLength, hash_key->h, (void **) &child)==FAILURE) {
 		if (parent_flags & ZEND_ACC_ABSTRACT) {
@@ -1818,15 +1814,22 @@ static zend_bool do_inherit_method_check(HashTable *child_function_table, zend_f
 		}
 	}
 
-	if (parent_flags & ZEND_ACC_ABSTRACT) {
+	if (EG(ze1_compatibility_mode)) {
+		if (parent_flags & ZEND_ACC_ABSTRACT) {
+			child->common.prototype = parent;
+			child->common.fn_flags |= ZEND_ACC_IMPLEMENTED_ABSTRACT;
+		} else {
+			child->common.prototype = parent->common.prototype;
+		}
+	} else {
 		child->common.prototype = parent;
-		child->common.fn_flags |= ZEND_ACC_IMPLEMENTED_ABSTRACT;
-	} else if (parent->common.prototype) {
-		child->common.prototype = parent->common.prototype;
+		if (parent_flags & ZEND_ACC_ABSTRACT) {
+			child->common.fn_flags |= ZEND_ACC_IMPLEMENTED_ABSTRACT;
+		}
 	}
 
 	if (!zend_do_perform_implementation_check(child)) {
-		zend_error(E_COMPILE_ERROR, "Declaration of %s::%s() must be the same as %s::%s()", ZEND_FN_SCOPE_NAME(child), child->common.function_name, ZEND_FN_SCOPE_NAME(child->common.prototype), child->common.prototype->common.function_name);
+		zend_error(E_COMPILE_ERROR, "Declaration of %s::%s() must be compatible with that of %s::%s()", ZEND_FN_SCOPE_NAME(child), child->common.function_name, ZEND_FN_SCOPE_NAME(child->common.prototype), child->common.prototype->common.function_name);
 	}
 
 	return 0;

Zend/zend_execute.c

@@ -382,7 +382,7 @@ static inline void zend_assign_to_object(znode *result, zval **object_ptr, znode
 	}
 	
 	/* here we are sure we are dealing with an object */
-	if (EG(implicit_clone)) {
+	if (EG(ze1_compatibility_mode)) {
 		SEPARATE_ZVAL_IF_NOT_REF(object_ptr);
 		object = *object_ptr;
 	}
@@ -2401,7 +2401,7 @@ int zend_init_ctor_call_handler(ZEND_OPCODE_HANDLER_ARGS)
 
 	/* We are not handling overloaded classes right now */
 	EX(object) = get_zval_ptr(&opline->op1, EX(Ts), &EG(free_op1), BP_VAR_R);
-	if (!PZVAL_IS_REF(EX(object)) || !EG(implicit_clone)) {
+	if (!PZVAL_IS_REF(EX(object)) || !EG(ze1_compatibility_mode)) {
 		EX(object)->refcount++; /* For $this pointer */
 	} else {
 		zval *this_ptr;
@@ -2459,7 +2459,7 @@ int zend_init_method_call_handler(ZEND_OPCODE_HANDLER_ARGS)
 	if (EX(fbc)->common.fn_flags & ZEND_ACC_STATIC) {
 		EX(object) = NULL;
 	} else {
-		if (!PZVAL_IS_REF(EX(object)) || !EG(implicit_clone)) {
+		if (!PZVAL_IS_REF(EX(object)) || !EG(ze1_compatibility_mode)) {
 			EX(object)->refcount++; /* For $this pointer */
 		} else {
 			zval *this_ptr;

Zend/zend_execute_API.c

@@ -132,7 +132,6 @@ void init_executor(TSRMLS_D)
 	EG(symtable_cache_ptr) = EG(symtable_cache)-1;
 	EG(symtable_cache_limit)=EG(symtable_cache)+SYMTABLE_CACHE_SIZE-1;
 	EG(no_extensions)=0;
-	EG(implicit_clone)=0;
 
 	EG(function_table) = CG(function_table);
 	EG(class_table) = CG(class_table);

Zend/zend_globals.h

@@ -193,7 +193,7 @@ struct _zend_executor_globals {
 	zend_bool in_autoload;
 	zend_bool bailout_set;
 	zend_bool full_tables_cleanup;
-	zend_bool implicit_clone;
+	zend_bool ze1_compatibility_mode;
 
 	/* for extended information support */
 	zend_bool no_extensions;

Zend/zend_variables.c

@@ -154,7 +154,7 @@ ZEND_API int _zval_copy_ctor(zval *zvalue ZEND_FILE_LINE_DC)
 			{
 				TSRMLS_FETCH();
 
-				if (EG(implicit_clone)) {
+				if (EG(ze1_compatibility_mode)) {
 					zvalue->value.obj = zvalue->value.obj.handlers->clone_obj(zvalue TSRMLS_CC);
 				} else {
 					Z_OBJ_HT_P(zvalue)->add_ref(zvalue TSRMLS_CC);