Reminds me of an anecdote from The Pragmatic Programmer: Andy once worked on a large graphics application. Nearing release, the testers reported that the appli

Reminds me of an anecdote from The Pragmatic Programmer: Andy once worked on a large graphics application. Nearing release, the testers reported that the application crashed every time they painted a stroke with a particular brush. The programmer responsible argued that there was nothing wrong with it; he had tried painting with it, and it worked just fine. This dialog went back and forth for several days, with tempers rapidly rising. Finally, we got them together in the same room. The tester selected the brush tool and painted a stroke from the upper right corner to the lower left corner. The application exploded. "Oh," said the programmer, in a small voice, who then sheepishly admitted that he had made test strokes only from the lower left to the upper right, which did not expose the bug.