streams: Checking if a stream is castable should not emit warnings for user defined streams

Closes GH-10435

NEWS

@@ -14,6 +14,7 @@ PHP                                                                        NEWS
     that is unset in error handler). (Girgias)
   . Fixed bug GH-12102 (Incorrect compile error when using array access on TMP
     value in function call). (ilutov)
+  . Fixed warning emitted when checking if a user stream is castable. (Girgias)
 
 - FPM:
   . Fixed GH-12077 (PHP 8.3.0RC1 borked socket-close-on-exec.phpt).

main/streams/userspace.c

@@ -1384,6 +1384,8 @@ static int php_userstreamop_cast(php_stream *stream, int castas, void **retptr)
 	php_stream * intstream = NULL;
 	int call_result;
 	int ret = FAILURE;
+	/* If we are checking if the stream can cast, no return pointer is provided, so do not emit errors */
+	bool report_errors = retptr;
 
 	ZVAL_STRINGL(&func_name, USERSTREAM_CAST, sizeof(USERSTREAM_CAST)-1);
 
@@ -1400,8 +1402,10 @@ static int php_userstreamop_cast(php_stream *stream, int castas, void **retptr)
 
 	do {
 		if (call_result == FAILURE) {
+			if (report_errors) {
 				php_error_docref(NULL, E_WARNING, "%s::" USERSTREAM_CAST " is not implemented!",
 						ZSTR_VAL(us->wrapper->ce->name));
+			}
 			break;
 		}
 		if (!zend_is_true(&retval)) {
@@ -1409,13 +1413,17 @@ static int php_userstreamop_cast(php_stream *stream, int castas, void **retptr)
 		}
 		php_stream_from_zval_no_verify(intstream, &retval);
 		if (!intstream) {
+			if (report_errors) {
 				php_error_docref(NULL, E_WARNING, "%s::" USERSTREAM_CAST " must return a stream resource",
 						ZSTR_VAL(us->wrapper->ce->name));
+			}
 			break;
 		}
 		if (intstream == stream) {
+			if (report_errors) {
 				php_error_docref(NULL, E_WARNING, "%s::" USERSTREAM_CAST " must not return itself",
 						ZSTR_VAL(us->wrapper->ce->name));
+			}
 			intstream = NULL;
 			break;
 		}

tests/output/stream_isatty_non_castable_userwrapper.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Non castable user-space streams (stream_cast())
+--FILE--
+<?php
+class test_wrapper {
+    public $context;
+    public $return_value;
+    function stream_open($path, $mode, $openedpath) {
+        return true;
+    }
+    function stream_eof() {
+        return false;
+    }
+}
+
+stream_wrapper_register('test', 'test_wrapper');
+$fd = fopen("test://foo","r");
+var_dump(stream_isatty($fd));
+
+?>
+--EXPECT--
+bool(false)