Raise ValueError when trying to save empty image

Tests/test_file_jpeg.py

@@ -68,6 +68,13 @@ def test_sanity(self):
             assert im.format == "JPEG"
             assert im.get_format_mimetype() == "image/jpeg"
 
+    @pytest.mark.parametrize("size", ((1, 0), (0, 1), (0, 0)))
+    def test_zero(self, size, tmp_path):
+        f = str(tmp_path / "temp.jpg")
+        im = Image.new("RGB", size)
+        with pytest.raises(ValueError):
+            im.save(f)
+
     def test_app(self):
         # Test APP/COM reader (@PIL135)
         with Image.open(TEST_FILE) as im:

src/PIL/JpegImagePlugin.py

@@ -632,6 +632,9 @@ def _save(im, fp, filename):
     except KeyError as e:
         raise OSError(f"cannot write mode {im.mode} as JPEG") from e
 
+    if im.width == 0 or im.height == 0:
+        raise ValueError("cannot write empty image as JPEG")
+
     info = im.encoderinfo
 
     dpi = [round(x) for x in info.get("dpi", (0, 0))]