With Pillow 3.2.0 on Python 3 (and on Python 2, with the fix in #1985), running the very same code as in #1592 with the very same image slightly edited, the following traceback occurs:

Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\PIL\ImagePalette.py", line 97, in getcolor
    return self.colors[color]
KeyError: (255, 255, 255)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "deborder.py", line 30, in <module>
    deborder(sys.argv[1])
  File "deborder.py", line 20, in deborder
    draw.line((topLeft, topRight),       fill=(255, 255, 255))
  File "C:\Python34\lib\site-packages\PIL\ImageDraw.py", line 177, in line
    ink, fill = self._getink(fill)
  File "C:\Python34\lib\site-packages\PIL\ImageDraw.py", line 124, in _getink
    ink = self.palette.getcolor(ink)
  File "C:\Python34\lib\site-packages\PIL\ImagePalette.py", line 108, in getcolor
    self.palette[index+256] = color[1]
IndexError: list assignment index out of range

Before the #1985 fix, the error is an IndexError: list assignment index out of range. After, it persists as an IndexError: bytearray index out of range, however.

From what I can tell, self.palette is shorter than 256 elements, and can therefore not take an assignment to index index+256. In this case, index is 0, as len(self.colors) in getcolor for this image is 0, which I find a bit odd.

Since the image is almost exactly the one used in #1592, this may be related. The difference is this one is edited in ImageMagick to make the outer 1px border white (#FFFFFF).

The very same code as in #1592 causes the error:

# -*- coding: utf-8 -*-

from PIL import Image, ImageDraw

def deborder(filename):
    frame = Image.open(filename)
    frameNo = 0
    while True:
        try:
            frame.seek(frameNo)
        except EOFError:
            break
        draw = ImageDraw.Draw(frame)

        topLeft = (0, 0)
        topRight = (frame.size[0] - 1, 0)
        bottomLeft = (0, frame.size[1] - 1)
        bottomRight = (frame.size[0] - 1, frame.size[1] - 1)

        draw.line((topLeft, topRight),       fill=(255, 255, 255))
        draw.line((topLeft, bottomLeft),     fill=(255, 255, 255))
        draw.line((bottomLeft, bottomRight), fill=(255, 255, 255))
        draw.line((topRight, bottomRight),   fill=(255, 255, 255))

        frameNo += 1

    frame.save('resave-'+filename, save_all=True)

deborder('no.gif')

With the following image, for example (while the error occurs with the exact image in #1592 edited a bit, I chose one with a different glyph to avoid future confusion):