execute addObject, but NSMutableArray has no object
<p>I try to use to codes below to add object to <code>NSMutableArray</code></p>

<pre><code>NSMutableArray* multipartData;
- (void)processDataChunk:(NSData *)postDataChunk
{
    if (!postHeaderOK)
    {
        UInt16 separatorBytes = 0x0A0D;
        NSData* separatorData = [NSData dataWithBytes:&amp;separatorBytes length:2];

        for (int i = 0; i &lt; [postDataChunk length] - l; i++)
        {
            NSRange searchRange = {i, l};

            if ([[postDataChunk subdataWithRange:searchRange] isEqualToData:separatorData])
            {
                NSRange newDataRange = {dataStartIndex, i - dataStartIndex};
                dataStartIndex = i + l;
                i += l - 1;
                NSData *newData = [postDataChunk subdataWithRange:newDataRange];

                if ([newData length])
                {
                    [multipartData addObject:newData]; //A:set break point here
                }
            }
        }
    }
}
</code></pre>

<p>I set breakpoint at A:, and found that newData is not nil.</p>

<p>What is wrong with my codes?</p>

<p>Welcome any comment</p>
