From 8ba0d513fa0068a241a25fbb6db09315fa3309cc Mon Sep 17 00:00:00 2001
From: Juan Linietsky <reduzio@gmail.com>
Date: Thu, 22 Nov 2018 23:21:03 -0300
Subject: [PATCH] Added missing path verification on Unix, closes #20762

---
 drivers/unix/dir_access_unix.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/unix/dir_access_unix.cpp b/drivers/unix/dir_access_unix.cpp
index 929e67faa97..e4b652cdce9 100644
--- a/drivers/unix/dir_access_unix.cpp
+++ b/drivers/unix/dir_access_unix.cpp
@@ -328,6 +328,17 @@ Error DirAccessUnix::change_dir(String p_dir) {
 		return ERR_INVALID_PARAMETER;
 	}
 
+	String base = _get_root_path();
+	if (base != String()) {
+		ERR_FAIL_COND_V(getcwd(real_current_dir_name, 2048) == NULL, ERR_BUG);
+		String new_dir;
+		new_dir.parse_utf8(real_current_dir_name);
+
+		if (!new_dir.begins_with(base)) {
+			try_dir = current_dir; //revert
+		}
+	}
+
 	// the directory exists, so set current_dir to try_dir
 	current_dir = try_dir;
 	ERR_FAIL_COND_V(chdir(prev_dir.utf8().get_data()) != 0, ERR_BUG);