Return from ImagingFill early if image has a zero dimension

Tests/test_image.py

@@ -512,6 +512,11 @@ class TestImage:
         i = Image.new("RGB", [1, 1])
         assert isinstance(i.size, tuple)
 
+    @pytest.mark.parametrize("size", ((0, 100000000), (100000000, 0)))
+    @pytest.mark.timeout(0.5)
+    def test_empty_image(self, size):
+        Image.new("RGB", size)
+
     def test_storage_neg(self):
         # Storage.c accepted negative values for xsize, ysize.  Was
         # test_neg_ppm, but the core function for that has been

src/libImaging/Fill.c

@@ -24,6 +24,11 @@ ImagingFill(Imaging im, const void *colour) {
     int x, y;
     ImagingSectionCookie cookie;
 
+    /* 0-width or 0-height image. No need to do anything */
+    if (!im->linesize || !im->ysize) {
+        return im;
+    }
+
     if (im->type == IMAGING_TYPE_SPECIAL) {
         /* use generic API */
         ImagingAccess access = ImagingAccessNew(im);