Fixed writing int as ASCII tag

Tests/test_file_tiff_metadata.py

@@ -185,20 +185,21 @@ def test_iptc(tmp_path):
         im.save(out)
 
 
-def test_writing_bytes_to_ascii(tmp_path):
+def test_writing_other_types_to_ascii(tmp_path):
     im = hopper()
     info = TiffImagePlugin.ImageFileDirectory_v2()
 
     tag = TiffTags.TAGS_V2[271]
     assert tag.type == TiffTags.ASCII
 
-    info[271] = b"test"
-
     out = str(tmp_path / "temp.tiff")
+    for (value, expected) in {b"test": "test", 1: "1"}.items():
+        info[271] = value
+
         im.save(out, tiffinfo=info)
 
         with Image.open(out) as reloaded:
-        assert reloaded.tag_v2[271] == "test"
+            assert reloaded.tag_v2[271] == expected
 
 
 def test_writing_int_to_bytes(tmp_path):

src/PIL/TiffImagePlugin.py

@@ -732,6 +732,8 @@ class ImageFileDirectory_v2(MutableMapping):
     @_register_writer(2)
     def write_string(self, value):
         # remerge of https://github.com/python-pillow/Pillow/pull/1416
+        if isinstance(value, int):
+            value = str(value)
         if not isinstance(value, bytes):
             value = value.encode("ascii", "replace")
         return value + b"\0"