syntax: fix overflow for big counted repetitions #996
Merged
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This fixes a bug where the calculation for the min/max length of a regex could overflow if the counted repetitions in the pattern are big enough. The panic only happens when debug assertions are enabled, which means there is no panic by default in release mode.
One may wonder whether other bad things happen in release mode though, since in that case, the arithmetic will wrap around instead. Since this is in new code and since the regex crate doesn't yet utilize the min/max attributes of an Hir, the wrap around in this case is completely innocuous.
Fixes #995