fix: prevent fd leak in TraversalType2 implementation

Author: Johnson-zs

src/libappimage/core/impl/TraversalType2.cpp

@@ -8,6 +8,7 @@
  extern "C" {
 #include <squashfuse.h>
 #include <squashfs_fs.h>
+#include <squashfuse/util.h>
 }
 
 // system
@@ -52,15 +53,25 @@ class TraversalType2::Priv {
         rootInodeId = sqfs_inode_root(&fs);
         err = sqfs_traverse_open(&trv, &fs, rootInodeId);
         if (err != SQFS_OK) {
+            // Save the file descriptor before destroying the fs structure
+            sqfs_fd_t fd = fs.fd;
             sqfs_destroy(&fs);
+            // Close the file descriptor to prevent fd leak
+            sqfs_fd_close(fd);
             throw IOError("sqfs_traverse_open error");
         }
     }
 
     virtual ~Priv() {
         sqfs_traverse_close(&trv);
 
+        // Save the file descriptor before destroying the fs structure
+        sqfs_fd_t fd = fs.fd;
+
         sqfs_destroy(&fs);
+
+        // Close the file descriptor to prevent fd leak
+        sqfs_fd_close(fd);
     }
 
     bool isCompleted() const {