Fix GH-14481: realpath() and SplFileInfo::getRealPath inside Phar

realpath() and SplFileInfo::getRealPath() route directly through
VCWD_REALPATH, which has no notion of stream wrappers. For a phar://
URL the call chain treats the URI as relative, prepends CWD, and
stat()s a nonsense path, so existing entries inside a Phar return
false even though file_exists()/is_file()/include all see them.

Before VCWD_REALPATH, look up the stream wrapper for the path. If a
non-plain, non-URL wrapper supplies url_stat and reports SUCCESS,
return the input string; on FAILURE, return false. Plain paths (and
file:// URLs that resolve back to the plain-files wrapper) keep the
existing VCWD_REALPATH semantics: realpath cache, ZTS access guard,
and open_basedir check. For phar URLs, open_basedir is enforced by
the wrapper's own url_stat, matching how is_file() and file_exists()
behave today.

The !wrapper->is_url guard keeps URL-style wrappers (http://, ftp://,
data://, user wrappers registered with STREAM_IS_URL) on the existing
false return so realpath() does not gain network or third-party
url_stat side effects. In-tree, only phar matches the new branch.
User wrappers registered without STREAM_IS_URL that implement
url_stat will now have url_stat called from realpath().

PharFileInfo, SplFileObject, DirectoryIterator,
RecursiveDirectoryIterator, and FilesystemIterator inherit
SplFileInfo::getRealPath and pick up the fix.

Closes GH-14481

Author: iliaal

ext/phar/tests/gh14481.phpt

@@ -0,0 +1,61 @@
+--TEST--
+GH-14481 (realpath() and SplFileInfo::getRealPath inside Phar)
+--EXTENSIONS--
+phar
+--INI--
+phar.readonly=0
+--FILE--
+<?php
+$file = __DIR__ . DIRECTORY_SEPARATOR . 'gh14481.phar';
+@unlink($file);
+
+$phar = new Phar($file);
+$phar->addFromString('inner.php', "<?php echo 'hi';");
+$phar->setStub("<?php __HALT_COMPILER();");
+unset($phar);
+
+$existing = "phar://" . $file . "/inner.php";
+$missing  = "phar://" . $file . "/nope.php";
+
+echo "realpath existing entry:\n";
+var_dump(realpath($existing));
+
+echo "realpath missing entry:\n";
+var_dump(realpath($missing));
+
+echo "SplFileInfo existing entry:\n";
+var_dump((new SplFileInfo($existing))->getRealPath());
+
+echo "SplFileInfo missing entry:\n";
+var_dump((new SplFileInfo($missing))->getRealPath());
+
+echo "PharFileInfo existing entry:\n";
+var_dump((new PharFileInfo($existing))->getRealPath());
+
+echo "RecursiveIteratorIterator entry:\n";
+foreach (new RecursiveIteratorIterator(new Phar($file)) as $info) {
+    var_dump($info->getRealPath());
+}
+
+echo "plain-filesystem branch unaffected:\n";
+var_dump(realpath(__FILE__) === __FILE__);
+?>
+--CLEAN--
+<?php
+@unlink(__DIR__ . DIRECTORY_SEPARATOR . 'gh14481.phar');
+?>
+--EXPECTF--
+realpath existing entry:
+string(%d) "phar://%sgh14481.phar/inner.php"
+realpath missing entry:
+bool(false)
+SplFileInfo existing entry:
+string(%d) "phar://%sgh14481.phar/inner.php"
+SplFileInfo missing entry:
+bool(false)
+PharFileInfo existing entry:
+string(%d) "phar://%sgh14481.phar/inner.php"
+RecursiveIteratorIterator entry:
+string(%d) "phar://%sgh14481.phar/inner.php"
+plain-filesystem branch unaffected:
+bool(true)

ext/spl/spl_directory.c

@@ -1244,6 +1244,17 @@ PHP_METHOD(SplFileInfo, getRealPath)
 		filename = intern->file_name ? ZSTR_VAL(intern->file_name) : NULL;
 	}
 
+	if (filename) {
+		const char *path_to_open = filename;
+		php_stream_wrapper *wrapper = php_stream_locate_url_wrapper(filename, &path_to_open, 0);
+		if (wrapper && wrapper != &php_plain_files_wrapper && !wrapper->is_url && wrapper->wops && wrapper->wops->url_stat) {
+			php_stream_statbuf ssb;
+			if (wrapper->wops->url_stat(wrapper, path_to_open, PHP_STREAM_URL_STAT_QUIET, &ssb, NULL) == 0) {
+				RETURN_STRING(filename);
+			}
+			RETURN_FALSE;
+		}
+	}
 
 	if (filename && VCWD_REALPATH(filename, buff)) {
 #ifdef ZTS

ext/standard/file.c

@@ -2102,6 +2102,16 @@ PHP_FUNCTION(realpath)
 		Z_PARAM_PATH(filename, filename_len)
 	ZEND_PARSE_PARAMETERS_END();
 
+	const char *path_to_open = filename;
+	php_stream_wrapper *wrapper = php_stream_locate_url_wrapper(filename, &path_to_open, 0);
+	if (wrapper && wrapper != &php_plain_files_wrapper && !wrapper->is_url && wrapper->wops && wrapper->wops->url_stat) {
+		php_stream_statbuf ssb;
+		if (wrapper->wops->url_stat(wrapper, path_to_open, PHP_STREAM_URL_STAT_QUIET, &ssb, NULL) == 0) {
+			RETURN_STRINGL(filename, filename_len);
+		}
+		RETURN_FALSE;
+	}
+
 	if (VCWD_REALPATH(filename, resolved_path_buff)) {
 		if (php_check_open_basedir(resolved_path_buff)) {
 			RETURN_FALSE;