malloc error for newbie

[David]

Hi,

Very new to python. When I uncomment the line
#        self.im.putpalette(mkpalette())
in the following code, I get the error:

python $ ./mandelbrot.py
Python(2860) malloc: ***  Deallocation of a pointer not malloced:
0xff000000; This could be a double free(), or free() called with the
middle of an allocated block; Try setting environment variable
MallocHelp to see tools to help debug

I don't have the expertise to get by this error. Can someone help?

Thanks.

#! /usr/local/bin/python
# Filename: mandelbrot.py

import Image, ImagePalette

def mkpalette():
    global palette
    palette = [0,0,0]
    for i in range(256):
        palette.extend([i*5%200+55,i*7%200+55,i*11%200+55])
    return palette

class Mandelbrot:

    def __init__(self,filename='mandelbrot.png',
                 size=(512,512),
                 n=64,
                 box=((-2,1.25), (0.5,-1.25))):
        self.filename=filename
        self.size=size
        self.n=n
        self.uleft=box[0]
        self.lright=box[1]
        self.width=self.lright[0]-self.uleft[0]
        self.height=self.uleft[1]-self.lright[1]

    def newimage(self):
        self.im=Image.new('P', self.size)
#        self.im.putpalette(mkpalette())

    def compute(self):
        self.newimage()

def test():
    f=Mandelbrot(filename='mandelbrot.png',
                 size=(512,512),
                 n=64,
                 box=((-2,1.25), (0.5,-1.25)))
    f.compute()

if __name__=='__main__':
    test()