dev(narugo): fix nai decode error

imgutils/sd/nai/extract.py

@@ -164,7 +164,10 @@
             raise ValueError(f'Image magic number mismatch, '
                              f'{self._magic_bytes!r} expected but {read_magic!r}.')
 
-        read_len = reader.read_32bit_integer() // 8
+        next_int = reader.read_32bit_integer()
+        if next_int is None:
+            raise ValueError('No next int32 to read.')
+        read_len = next_int // 8
         json_data = reader.get_next_n_bytes(read_len)
 
         json_data = json.loads(gzip.decompress(json_data).decode("utf-8"))

imgutils/sd/nai/metadata.py

@@ -15,6 +15,7 @@
 import json
 import os
 import warnings
+import zlib
 from dataclasses import dataclass
 from typing import Optional, Union
 
@@ -95,7 +96,11 @@ def _get_naimeta_raw(image: ImageTyping) -> dict:
     image = load_image(image, force_background=None, mode=None)
     try:
         return ImageLsbDataExtractor().extract_data(image)
-    except (ValueError, json.JSONDecodeError):
+    except (ValueError, json.JSONDecodeError, zlib.error, OSError, UnicodeDecodeError):
+        # ValueError: binary data with wrong format
+        # json.JSONDecodeError: zot a json-formatted data
+        # zlib.error, OSError: not zlib compressed binary data
+        # UnicodeDecodeError: cannot decode as utf-8 text
         return image.info or {}
 
 

test/sd/test_nai.py

@@ -205,3 +205,10 @@ def test_save_image_with_naimeta_both_no_with_title(self, nai3_clear_file, nai3_
                     save_pnginfo=False, add_lsb_meta=False,
                 )
             assert get_naimeta_from_image('image.png') is None
+
+    @pytest.mark.parametrize(['file'], [
+        ('118519492_p0.png',),
+        ('118438300_p1.png',),
+    ])
+    def test_image_error_with_wrong_format(self, file):
+        assert get_naimeta_from_image(get_testfile(file)) is None