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Author: sj-i

Zend/zend_inheritance.c

@@ -2206,6 +2206,13 @@ static void zend_do_traits_method_binding(zend_class_entry *ce, zend_class_entry
 
 static zend_class_entry* find_first_constant_definition(zend_class_entry *ce, zend_class_entry **traits, size_t current_trait, zend_string *constant_name, zend_class_entry *colliding_ce) /* {{{ */
 {
+	/* This function is used to show the place of the existing conflicting
+	 * definition in error messages when conflicts occur. Since trait constants
+	 * are flattened into the constants table of the composing class, and thus
+	 * we lose information about which constant was defined in which trait, a
+	 * process like this is needed to find the location of the first definition
+	 * of the constant from traits.
+	 */
 	size_t i;
 
 	if (colliding_ce == ce) {
@@ -2216,7 +2223,7 @@ static zend_class_entry* find_first_constant_definition(zend_class_entry *ce, ze
 			}
 		}
 	}
-
+	/* Traits don't have it, then the composing class (or trait) itself has it. */
 	return colliding_ce;
 }
 /* }}} */
@@ -2275,7 +2282,16 @@ static void zend_do_traits_constant_binding(zend_class_entry *ce, zend_class_ent
 					ce->ce_flags |= ZEND_ACC_HAS_AST_CONSTANTS;
 				}
 
+				/* Unlike interface implementations and class inheritances,
+				 * access control of the trait constants is done by the scope
+				 * of the composing class. So let's replace the ce here.
+				 * And the result of this, the values, doc comments, and
+				 * attributes associated with the copied zend_class_constant
+				 * are destroyed at the time of destroying the class entry of
+				 * the composing class.
+				 */
 				constant->ce = ce;
+
 				Z_TRY_ADDREF(constant->value);
 				constant->doc_comment = constant->doc_comment ? zend_string_copy(constant->doc_comment) : NULL;
 				if (constant->attributes && (!(GC_FLAGS(constant->attributes) & IS_ARRAY_IMMUTABLE))) {