Only preserve IPTC_NAA_CHUNK tag if type if BYTE or UNDEFINED

Author: radarhere

Tests/test_file_tiff.py

@@ -621,6 +621,19 @@ def test_roundtrip_tiff_uint16(self, tmp_path: Path) -> None:
 
             assert_image_equal_tofile(im, tmpfile)
 
+    def test_iptc(self, tmp_path: Path) -> None:
+        # Do not preserve IPTC_NAA_CHUNK by default if type is LONG
+        outfile = str(tmp_path / "temp.tif")
+        im = hopper()
+        ifd = TiffImagePlugin.ImageFileDirectory_v2()
+        ifd[33723] = 1
+        ifd.tagtype[33723] = 4
+        im.tag_v2 = ifd
+        im.save(outfile)
+
+        with Image.open(outfile) as im:
+            assert 33723 not in im.tag_v2
+
     def test_rowsperstrip(self, tmp_path: Path) -> None:
         outfile = str(tmp_path / "temp.tif")
         im = hopper()

src/PIL/TiffImagePlugin.py

@@ -1665,7 +1665,10 @@ def _save(im, fp, filename):
             PHOTOSHOP_CHUNK,
             XMP,
         ):
-            if key in im.tag_v2:
+            if key in im.tag_v2 and not (
+                key == IPTC_NAA_CHUNK
+                and im.tag_v2.tagtype[key] not in (TiffTags.BYTE, TiffTags.UNDEFINED)
+            ):
                 ifd[key] = im.tag_v2[key]
                 ifd.tagtype[key] = im.tag_v2.tagtype[key]