diff kitten: Fix directory diffing with removed binary files failing

Fixes #2378

docs/changelog.rst

@@ -35,6 +35,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Fix border/margin/padding sizes not being recalculated on DPI change
   (:iss:`2346`)
 
+- diff kitten: Fix directory diffing with removed binary files failing
+  (:iss:`2378`)
+
 - macOS: Fix menubar title not updating on OS Window focus change (:iss:`2350`)
 
 - Fix rendering of combining characters with fonts that have glyphs for

kittens/diff/collect.py

@@ -134,7 +134,7 @@ def raw_data_for_path(path):
 
 
 def is_image(path):
-    return mime_type_for_path(path).startswith('image/')
+    return mime_type_for_path(path).startswith('image/') if path else False
 
 
 @lru_cache(maxsize=1024)