- Added check for abstract class

abstract class foo { }
  class T { use foo; } // T cannot use foo - it is not a trait

- Added check for trait on NEW 

  trait a { }
  new a; // Cannot instantiate trait a

# Tests for errors comming soon :)

Zend/zend_compile.c

@@ -4518,7 +4518,7 @@ void zend_do_implements_trait(znode *trait_name TSRMLS_DC) /* {{{ */
 	opline->opcode = ZEND_ADD_TRAIT;
 	SET_NODE(opline->op1, &CG(implementing_class));
 	zend_resolve_class_name(trait_name, &opline->extended_value, 0 TSRMLS_CC);
-	opline->extended_value = (opline->extended_value & ~ZEND_FETCH_CLASS_MASK) | ZEND_FETCH_CLASS_TRAIT;
+	opline->extended_value = ZEND_FETCH_CLASS_TRAIT;
 	opline->op2_type = IS_CONST;
 	opline->op2.constant = zend_add_class_name_literal(CG(active_op_array), &trait_name->u.constant TSRMLS_CC);
 	CG(active_class_entry)->num_traits++;

Zend/zend_vm_def.h

@@ -3230,6 +3230,8 @@ ZEND_VM_HANDLER(68, ZEND_NEW, ANY, ANY)
 
 		if (EX_T(opline->op1.var).class_entry->ce_flags & ZEND_ACC_INTERFACE) {
 			class_type = "interface";
+		} else if (EX_T(opline->op1.var).class_entry->ce_flags & ZEND_ACC_TRAIT) {
+			class_type = "trait";
 		} else {
 			class_type = "abstract class";
 		}
@@ -4663,7 +4665,7 @@ ZEND_VM_HANDLER(154, ZEND_ADD_TRAIT, ANY, ANY)
                                              opline->extended_value TSRMLS_CC);
 	
 	if (trait) {
-		if (!(trait->ce_flags & ZEND_ACC_TRAIT)) {
+		if (!((trait->ce_flags & ~ZEND_ACC_EXPLICIT_ABSTRACT_CLASS) & ZEND_ACC_TRAIT)) {
 			zend_error_noreturn(E_ERROR, "%s cannot use %s - it is not a trait", ce->name, trait->name);
 		}
 		zend_do_implement_trait(ce, trait TSRMLS_CC);

Zend/zend_vm_execute.h

@@ -520,6 +520,8 @@ static int ZEND_FASTCALL  ZEND_NEW_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
 
 		if (EX_T(opline->op1.var).class_entry->ce_flags & ZEND_ACC_INTERFACE) {
 			class_type = "interface";
+		} else if (EX_T(opline->op1.var).class_entry->ce_flags & ZEND_ACC_TRAIT) {
+			class_type = "trait";
 		} else {
 			class_type = "abstract class";
 		}
@@ -691,7 +693,7 @@ static int ZEND_FASTCALL  ZEND_ADD_TRAIT_SPEC_HANDLER(ZEND_OPCODE_HANDLER_ARGS)
                                              opline->extended_value TSRMLS_CC);
 
 	if (trait) {
-		if (!(trait->ce_flags & ZEND_ACC_TRAIT)) {
+		if (!((trait->ce_flags & ~ZEND_ACC_EXPLICIT_ABSTRACT_CLASS) & ZEND_ACC_TRAIT)) {
 			zend_error_noreturn(E_ERROR, "%s cannot use %s - it is not a trait", ce->name, trait->name);
 		}
 		zend_do_implement_trait(ce, trait TSRMLS_CC);