From 348b7a06f3fea50112bf939a6c729ce226b41cd9 Mon Sep 17 00:00:00 2001
From: sezanzeb <proxima@sezanzeb.de>
Date: Sun, 13 Aug 2023 12:36:59 +0200
Subject: [PATCH 1/2] Recurse m4a atoms to search for ilst

---
 mutagen/mp4/__init__.py | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/mutagen/mp4/__init__.py b/mutagen/mp4/__init__.py
index 9e1757ec..f9203517 100644
--- a/mutagen/mp4/__init__.py
+++ b/mutagen/mp4/__init__.py
@@ -340,17 +340,27 @@ def __init__(self, *args, **kwargs):
         if args or kwargs:
             self.load(*args, **kwargs)
 
-    def load(self, atoms, fileobj):
-        try:
-            path = atoms.path(b"moov", b"udta", b"meta", b"ilst")
-        except KeyError as key:
-            raise MP4MetadataError(key)
-
-        free = _find_padding(path)
-        self._padding = free.datalength if free is not None else 0
+    def load(self, atoms: Atoms, fileobj):
+        for atom in atoms.atoms:
+            if atom.children is not None:
+                self._recurse_atom(atom, fileobj)
+
+    def _recurse_atom(self, parent: Atom, fileobj):
+        """Recursively search for an ilst atom to read metadata from.
+
+        Recursing helps if the mp4/m4a container didn't store metadata correctly,
+        which is usually expected at moov.udta.meta.ilst"""
+        if parent.name != b"ilst":
+            for atom in parent.children:
+                if parent.name == b"meta" and atom.name == b"ilst":
+                    free = _find_padding([parent, atom])
+                    self._padding = free.datalength if free is not None else 0
+
+                if atom.children is not None and atom.name != 'ilst':
+                    self._recurse_atom(atom, fileobj)
+            return
 
-        ilst = path[-1]
-        for atom in ilst.children:
+        for atom in parent.children:
             ok, data = atom.read(fileobj)
             if not ok:
                 raise MP4MetadataError("Not enough data")

From 638751c5a5773a35e6482ba7df5b9c707566eb0b Mon Sep 17 00:00:00 2001
From: sezanzeb <proxima@sezanzeb.de>
Date: Sun, 13 Aug 2023 12:54:23 +0200
Subject: [PATCH 2/2] return early when children are None

---
 mutagen/mp4/__init__.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mutagen/mp4/__init__.py b/mutagen/mp4/__init__.py
index f9203517..e051e751 100644
--- a/mutagen/mp4/__init__.py
+++ b/mutagen/mp4/__init__.py
@@ -350,6 +350,9 @@ def _recurse_atom(self, parent: Atom, fileobj):
 
         Recursing helps if the mp4/m4a container didn't store metadata correctly,
         which is usually expected at moov.udta.meta.ilst"""
+        if parent.children is None:
+            return
+
         if parent.name != b"ilst":
             for atom in parent.children:
                 if parent.name == b"meta" and atom.name == b"ilst":