Nicollet.Net

This code summarizes some text by removing anything past 255 characters. It’s done before inserting things into a database, so that the brutal cut of a VARCHAR(255) doesn’t leave a truncated string but rather three nice dots.

function summarize($text)
{
  assert (is_string($text));
  if (strlen($text) < 255) return $text;
  return substr($text,0,253).'...';
}

Yet, however simple it might be, this function contains a bug. One day, your database will return a weird error when an user tries to save the data. If you’re lucky, it will happen to a lone user who will complain and move on. If you’re unlucky, it will happen during a million-line import and crash everything, or it will display strange things on the screenof every user around.

Can you find why?

Continue reading ‘Find the bug!’