Merge pull request #6986 from fcarron/fix_libtiff_file_pointer

Close file pointer copy in the libtiff encoder if still open

Tests/test_file_libtiff.py

@@ -1065,3 +1065,9 @@ class TestFileLibTiff(LibTiffTestCase):
         out = str(tmp_path / "temp.tif")
         with pytest.raises(SystemError):
             im.save(out, compression=compression)
+
+    def test_save_many_compressed(self, tmp_path):
+        im = hopper()
+        out = str(tmp_path / "temp.tif")
+        for _ in range(10000):
+            im.save(out, compression="jpeg")

src/PIL/TiffImagePlugin.py

@@ -1850,6 +1850,11 @@ def _save(im, fp, filename):
                 fp.write(data)
             if errcode:
                 break
+        if _fp:
+            try:
+                os.close(_fp)
+            except OSError:
+                pass
         if errcode < 0:
             msg = f"encoder error {errcode} when writing image file"
             raise OSError(msg)