Check for IntersectionType before calling isConstantScalarValue() in TypeCombinator::union()

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: phpstan-bot

src/Type/TypeCombinator.php

@@ -423,7 +423,7 @@ public static function doUnion(Type ...$types): Type
 			// a constant scalar refined by an accessory type ('Foo'&hasMethod(bar))
 			// stays with the other types so it is compared against the plain
 			// constant scalars and other refinements of the same value
-			if ($types[$i]->isConstantScalarValue()->yes() && !$types[$i] instanceof IntersectionType) {
+			if (!$types[$i] instanceof IntersectionType && $types[$i]->isConstantScalarValue()->yes()) {
 				$type = $types[$i];
 				$scalarTypes[get_class($type)][$type->describe(VerbosityLevel::cache())] = $type;
 				unset($types[$i]);

turbo-ext/src/TypeCombinator.cpp

@@ -1038,9 +1038,12 @@ class TypeCombinator
 		Level cacheLevel(PT_LC("cache"));
 		for (size_t i = 0; i < typesCount; i++) {
 			zval *type = types[i].raw();
-			zend_long isConstantScalarValue = callTrinary(type, PT_LC("isconstantscalarvalue"));
-			PT_FAIL_IF_NEG(isConstantScalarValue);
-			if (isConstantScalarValue == PT_TRI_YES && !isInstance(type, pt_ce_intersection_type)) {
+			zend_long isConstantScalarValue = PT_TRI_NO;
+			if (!isInstance(type, pt_ce_intersection_type)) {
+				isConstantScalarValue = callTrinary(type, PT_LC("isconstantscalarvalue"));
+				PT_FAIL_IF_NEG(isConstantScalarValue);
+			}
+			if (isConstantScalarValue == PT_TRI_YES) {
 				zv::Val description = describe(type, cacheLevel);
 				zend_string *key = describedKey(description);
 				if (UNEXPECTED(key == NULL)) return zv::Val();