Parsing algebraic expressions is always a pain. If you need to compute, say, 2+4*2, the answer should be the same as (2 + (4 *2)), not ((2 + 4) * 2) — in other words, the right answer is 10, not ...

URL Parsing Security Bugs. In their analysis, researchers came across eight high-severity vulnerabilities in third-party web-applications resulting from URL parsing confusion.