preserve UTF-16 surrogate pairs in MaskXmlInvalidCharacters - fixes #290#291
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FreeAndNil merged 1 commit intomasterfrom Apr 16, 2026
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The regex [^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD] operated on individual UTF-16 char units, causing both halves of a valid surrogate pair to be replaced, silently corrupting supplementary characters (U+10000–U+10FFFF) such as emoji in XML log output. Fix by prepending a surrogate-pair alternative to the regex so valid pairs are matched and preserved as a unit; only lone surrogates and other XML-illegal code units are replaced with the mask string. Also optimise CountSubstrings: use a char loop for single-character substrings (all current callers) and StringComparison.Ordinal for the multi-character CDATA token path. Add unit tests covering surrogate pair preservation, lone surrogates, and CountSubstrings edge cases.
fluffynuts
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Apr 16, 2026
FreeAndNil
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Feature/291-MaskXmlInvalidCharacters-surrogate-pairs
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This was referenced Apr 20, 2026
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fixes #290
The regex [^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD] operated on individual UTF-16 char units, causing both halves of a valid surrogate pair to be replaced, silently corrupting supplementary characters (U+10000–U+10FFFF) such as emoji in XML log output.
Fix by prepending a surrogate-pair alternative to the regex so valid pairs are matched and preserved as a unit; only lone surrogates and other XML-illegal code units are replaced with the mask string.
Also optimise CountSubstrings: use a char loop for single-character substrings (all current callers) and StringComparison.Ordinal for the multi-character CDATA token path.
Add unit tests covering surrogate pair preservation, lone surrogates, and CountSubstrings edge cases.