Fix handling of capture groups inside of negative lookarounds #97463
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The Regex compiler and source generator weren't uncapturing captures inside of a negative lookaround. That then leads both to subsequent backreferences matching when they shouldn't.
ghost
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Tagging subscribers to this area: @dotnet/area-system-text-regularexpressions Issue DetailsThe Regex compiler and source generator weren't uncapturing captures inside of a negative lookaround. That then leads both to subsequent backreferences matching when they shouldn't. Fixes #97455
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No analogous issue with positive lookarounds? |
Yes |
No, those captures are supposed to persist (and do). |
| @@ -114,6 +118,8 @@ private static IEnumerable<(string Pattern, string Input, RegexOptions Options, | |||
| yield return (@"(?<=\d?)a{4}", "123aaaaaaaaa", RegexOptions.None, 0, 12, true, "aaaa"); | |||
| yield return (@"(?<=a{3,5}[ab]*)1234", "aaaaaaa1234", RegexOptions.None, 0, 11, true, "1234"); | |||
| yield return (@"(\w)*?3(?<=33)$", "1233", RegexOptions.None, 0, 4, true, "1233"); | |||
| yield return (@"(?=(\d))4\1", "44", RegexOptions.None, 0, 2, true, "44"); | |||
| yield return (@"(?=(\d))4\1", "43", RegexOptions.None, 0, 2, false, ""); | |||
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| // Zero-width negative lookbehind assertion: Actual - "(\\w){6}(?<!XXX)def" | |||
| yield return (@"(\w){6}(?<!XXX)def", "XXXabcdef", RegexOptions.None, 0, 9, true, "XXXabcdef"); | |||
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@stephentoub are we covered for testing analogous case for negative lookbehind? eg., (?<!(b)a)\1 shouldn't match bb
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Probably not from a test perspective; the src fix covers both directions. Feel free to submit a pr.
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does https://regex101.com/r/jsQ12z/1 mean that regex101 is still using 6.0? |
More likely is it's using the interpreter |
The Regex compiler and source generator weren't uncapturing captures inside of a negative lookaround. That then leads both to subsequent backreferences matching when they shouldn't.
Fixes #97455