Removed unnecessary reinsertion of constants into the constant table when a constant with the same name passes the compatibility check.

Author: sj-i

Zend/zend_inheritance.c

@@ -2223,28 +2223,30 @@ static zend_class_entry* find_first_constant_definition(zend_class_entry *ce, ze
 
 static bool do_trait_constant_check(zend_class_entry *ce, zend_class_constant *trait_constant, zend_string *name, zend_class_entry **traits, size_t current_trait) /* {{{ */
 {
-	bool is_compatible = false;
 	uint32_t flags_mask = ZEND_ACC_PPP_MASK | ZEND_ACC_FINAL;
 
 	zval *zv = zend_hash_find_known_hash(&ce->constants_table, name);
 	if (zv == NULL) {
+		// No existing constant of the same name, so this one can be added
 		return true;
 	}
 
 	zend_class_constant *existing_constant = Z_PTR_P(zv);
 
 	if ((ZEND_CLASS_CONST_FLAGS(trait_constant) & flags_mask) == (ZEND_CLASS_CONST_FLAGS(existing_constant) & flags_mask)) {
-		is_compatible = check_trait_property_or_constant_value_compatibility(ce, &trait_constant->value, &existing_constant->value);
-	}
-	if (!is_compatible) {
-		zend_error_noreturn(E_COMPILE_ERROR,
-			"%s and %s define the same constant (%s) in the composition of %s. However, the definition differs and is considered incompatible. Class was composed",
-			ZSTR_VAL(find_first_constant_definition(ce, traits, current_trait, name, existing_constant->ce)->name),
-			ZSTR_VAL(trait_constant->ce->name),
-			ZSTR_VAL(name),
-			ZSTR_VAL(ce->name));
+		if (check_trait_property_or_constant_value_compatibility(ce, &trait_constant->value, &existing_constant->value)) {
+			// There is an existing constant which is compatible with the new one, so no need to add it
+			return false;
+		}
 	}
-	return is_compatible;
+
+	// There is an existing constant of the same name, and it conflicts with the new one, so let's throw a fatal error
+	zend_error_noreturn(E_COMPILE_ERROR,
+		"%s and %s define the same constant (%s) in the composition of %s. However, the definition differs and is considered incompatible. Class was composed",
+		ZSTR_VAL(find_first_constant_definition(ce, traits, current_trait, name, existing_constant->ce)->name),
+		ZSTR_VAL(trait_constant->ce->name),
+		ZSTR_VAL(name),
+		ZSTR_VAL(ce->name));
 }
 /* }}} */