Fix #78863: DirectoryIterator class silently truncates after a null byte

Since the constructor of DirectoryIterator and friends is supposed to
accepts paths (i.e. strings without NUL bytes), we must not accept
arbitrary strings.

(cherry picked from commit a5a1596)

ext/spl/spl_directory.c

@@ -708,10 +708,10 @@ void spl_filesystem_object_construct(INTERNAL_FUNCTION_PARAMETERS, zend_long cto
 
 	if (SPL_HAS_FLAG(ctor_flags, DIT_CTOR_FLAGS)) {
 		flags = SPL_FILE_DIR_KEY_AS_PATHNAME|SPL_FILE_DIR_CURRENT_AS_FILEINFO;
-		parsed = zend_parse_parameters(ZEND_NUM_ARGS(), "s|l", &path, &len, &flags);
+		parsed = zend_parse_parameters(ZEND_NUM_ARGS(), "p|l", &path, &len, &flags);
 	} else {
 		flags = SPL_FILE_DIR_KEY_AS_PATHNAME|SPL_FILE_DIR_CURRENT_AS_SELF;
-		parsed = zend_parse_parameters(ZEND_NUM_ARGS(), "s", &path, &len);
+		parsed = zend_parse_parameters(ZEND_NUM_ARGS(), "p", &path, &len);
 	}
 	if (SPL_HAS_FLAG(ctor_flags, SPL_FILE_DIR_SKIPDOTS)) {
 		flags |= SPL_FILE_DIR_SKIPDOTS;

ext/spl/tests/bug78863.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Bug #78863 (DirectoryIterator class silently truncates after a null byte)
+--FILE--
+<?php
+$dir = __DIR__ . '/bug78863';
+mkdir($dir);
+touch("$dir/bad");
+mkdir("$dir/sub");
+touch("$dir/sub/good");
+
+$it = new DirectoryIterator(__DIR__ . "/bug78863\0/sub");
+foreach ($it as $fileinfo) {
+    if (!$fileinfo->isDot()) {
+        var_dump($fileinfo->getFilename());
+    }
+}
+?>
+--EXPECTF--
+Fatal error: Uncaught UnexpectedValueException: DirectoryIterator::__construct() expects parameter 1 to be a valid path, string given in %s:%d
+Stack trace:
+#0 %s(%d): DirectoryIterator->__construct('%s')
+#1 {main}
+  thrown in %s on line %d
+--CLEAN--
+<?php
+$dir = __DIR__ . '/bug78863';
+unlink("$dir/sub/good");
+rmdir("$dir/sub");
+unlink("$dir/bad");
+rmdir($dir);
+?>