From 22bb757726cb82f5046c3dc56c358c1947314650 Mon Sep 17 00:00:00 2001
From: yangfl <yangfl@users.noreply.github.com>
Date: Wed, 19 Mar 2025 10:36:39 +0800
Subject: [PATCH] Remove PATH_MAX from realpath

POSIX.1-2008 ensures realpath() give a dynamically allocated buffer if
NULL is passed, which avoids using PATH_MAX, which may be too large to
fit in stack, or even undefined on some systems.
---
 common/filesystem.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/common/filesystem.cpp b/common/filesystem.cpp
index 5287a0c..766ee5c 100644
--- a/common/filesystem.cpp
+++ b/common/filesystem.cpp
@@ -100,10 +100,14 @@ bool changeDirectory(const UString & dir)
 }
 
 UString getAbsPath(const UString & path) {
-    char abs[PATH_MAX] = {};
+    char * abs = realpath(path.toLocal8Bit(), nullptr);
     // Last is a non-standard extension for non-existent files
-    if (realpath(path.toLocal8Bit(), abs) || abs[0] != '\0')
-        return UString(abs);
-    return path;
+    UString new_path;
+    if (abs)
+        new_path = UString(abs);
+    else
+        new_path = path;
+    free(abs);
+    return new_path;
 }
 #endif