waffle

HexColorPicker.m, circa one hour ago:

- (void)hcp_checkForUpdateUIFinish:(NSDictionary *)updateDict {
    /* Note: updateDict is by call site convention 
       already passed a retained dictionary */

    NSString *verdict = [[updateDict objectForKey:HexColorPickerUpdateVerdict] copy];
    [updateDict release];
    /* .. */
    if ([verdict isEqualToString:HexColorPickerUpdateNewerAvailable]) {
        NSString *infourl = [updateDict objectForKey:HexColorPickerUpdateNewerURL];
        if (updateInfoURL) [updateInfoURL release];
        updateInfoURL = [[NSURL alloc] initWithString:infourl];
        /* .. */
    }
    [verdict release];      
}

Did you spot it? If a newer version is available, you’re running Hex Color Picker outside of garbage collection and you’re unlucky, updateDict won’t just be released prematurely, but also be dealloced before an attempt is made to pull some more data (the new version URL) out of it. That might leave updateDict pointing to nil, messaging nil also returns nil which makes infourl nil and we end up feeding it to NSURL’s - initWithString:. Which produces an exception. Which takes down the entire application Hex Color Picker is hosted in.

Ruh-roh.

I’ve fixed this and pushed Hex Color Picker 1.6.1, which, in a delicious fit of irony, will expose every single Hex Color Picker user (of a version of such a vintage that it has the bug in it) to the conditions that trigger the bug.

I am reminded of O’Toole’s Commentary on Murphy’s Law: Murphy was an optimist.