Fixed #29705 -- Fixed ImageField RuntimeError crash for WebP files.

django/core/files/images.py

@@ -69,6 +69,10 @@ def get_image_dimensions(file_or_path, close=False):
                 # less bytes than expected. Skip and feed more data to the
                 # parser (ticket #24544).
                 pass
+            except RuntimeError:
+                # e.g. "RuntimeError: could not create decoder object" for
+                # WebP files. A different chunk_size may work.
+                pass
             if p.image:
                 return p.image.size
             chunk_size *= 2

tests/files/tests.py

@@ -343,6 +343,12 @@ class GetImageDimensionsTests(unittest.TestCase):
                 size = images.get_image_dimensions(fh)
                 self.assertEqual(size, (None, None))
 
+    def test_webp(self):
+        img_path = os.path.join(os.path.dirname(__file__), 'test.webp')
+        with open(img_path, 'rb') as fh:
+            size = images.get_image_dimensions(fh)
+        self.assertEqual(size, (540, 405))
+
 
 class FileMoveSafeTests(unittest.TestCase):
     def test_file_move_overwrite(self):