Catastrophic backtracking in SquidConfLexer #2191
Description
The CI run https://github.com/pygments/pygments/runs/7368863507?check_suite_focus=true timed out in test_random_input for SquidConfLexer.
The offending regex is very likely
ip_re = (
r'(?:(?:(?:[3-9]\d?|2(?:5[0-5]|[0-4]?\d)?|1\d{0,2}|0x0*[0-9a-f]{1,2}|'
r'0+[1-3]?[0-7]{0,2})(?:\.(?:[3-9]\d?|2(?:5[0-5]|[0-4]?\d)?|1\d{0,2}|'
r'0x0*[0-9a-f]{1,2}|0+[1-3]?[0-7]{0,2})){3})|(?!.*::.*::)(?:(?!:)|'
r':(?=:))(?:[0-9a-f]{0,4}(?:(?<=::)|(?<!::):)){6}(?:[0-9a-f]{0,4}'
r'(?:(?<=::)|(?<!::):)[0-9a-f]{0,4}(?:(?<=::)|(?<!:)|(?<=:)(?<!::):)|'
r'(?:25[0-4]|2[0-4]\d|1\d\d|[1-9]?\d)(?:\.(?:25[0-4]|2[0-4]\d|1\d\d|'
r'[1-9]?\d)){3}))'
)I'm pretty eager to dissect that!!