Fix nullable type pretty-printing

Author: nikic

Zend/tests/assert/expect_015.phpt

@@ -20,7 +20,7 @@ assert(0 && ($a = function () {
 	yield from $x;
 }));
 
-assert(0 && ($a = function &(array &$a, X $b = null) use ($c,&$d) : X {
+assert(0 && ($a = function &(array &$a, ?X $b = null) use ($c,&$d) : ?X {
 	abstract class A extends B implements C, D {
 		const X = 12;
 		const Y = self::X, Z = "aaa";
@@ -161,7 +161,7 @@ Warning: assert(): assert(0 && ($a = function () {
     yield from $x;
 })) failed in %sexpect_015.php on line %d
 
-Warning: assert(): assert(0 && ($a = function &(array &$a, X $b = null) use($c, &$d): X {
+Warning: assert(): assert(0 && ($a = function &(array &$a, ?X $b = null) use($c, &$d): ?X {
     abstract class A extends B implements C, D {
         const X = 12;
         const Y = self::X, Z = 'aaa';

Zend/zend_ast.c

@@ -1080,6 +1080,9 @@ static void zend_ast_export_ex(smart_str *str, zend_ast *ast, int priority, int
 			zend_ast_export_ex(str, decl->child[1], 0, indent);
 			if (decl->child[3]) {
 				smart_str_appends(str, ": ");
+				if (decl->child[3]->attr & ZEND_TYPE_NULLABLE) {
+					smart_str_appendc(str, '?');
+				}
 				zend_ast_export_ns_name(str, decl->child[3], 0, indent);
 			}
 			if (decl->child[2]) {
@@ -1614,6 +1617,9 @@ static void zend_ast_export_ex(smart_str *str, zend_ast *ast, int priority, int
 			break;
 		case ZEND_AST_PARAM:
 			if (ast->child[0]) {
+				if (ast->child[0]->attr & ZEND_TYPE_NULLABLE) {
+					smart_str_appendc(str, '?');
+				}
 				zend_ast_export_ns_name(str, ast->child[0], 0, indent);
 				smart_str_appendc(str, ' ');
 			}