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Replace escaped surrogates in CSS with U+FFFD - #274
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A CSS escape for the first or last surrogate code point, e.g.
content: "\D800"or.a\DFFF { }, throws anArgumentOutOfRangeExceptionin the lexer and the whole document fails to load. CSS Syntax 3 says that zero, a surrogate or anything above U+10FFFF becomes U+FFFD instead. The range check inIsInvalid()compared against0xD800and0xDFFFexclusively, so the two boundaries slipped through and ended up inchar.ConvertFromUtf32, which rejects them. The check is now inclusive, zero and code points above U+10FFFF were already handled correctly.How to test this PR?
CI should succeed.
LexerInvalidEscapedCodePointInStringandLexerInvalidEscapedCodePointInIdentcover zero, the surrogate range, the values right next to it and code points above U+10FFFF, the\D800and\DFFFcases fail on master.