Bug in UIKit string drawing method?

Question

In order to replicate a crash I was having in my application, I had to create a sample with a slightly exaggerated repeat rate that might not be practical, but one that demo

Answer 1

An easy workaround for this is to replace NSString with NSAttributedString.

The crash test that @maq listed does not crash if modified like this:

-(void)threadFunc:(UIFont *)font {
    @autoreleasepool {
        NSString *string = @" ";
        NSMutableAttributedString *test = [[NSMutableAttributedString alloc] initWithString:string];
        CGRect r = {{0,0},{50,50}};
        UIGraphicsBeginImageContextWithOptions(r.size, YES, 0);
        for(;;) {
            @autoreleasepool {
                 UIFont *font=[UIFont fontWithName:@"Helvetica-Bold" size:30.0f];
                [test addAttribute:NSFontAttributeName value:font range:NSMakeRange(0, test.length)];
                [test drawAtPoint:r.origin];
            }
        }
        UIGraphicsEndImageContext();
    }
}