case insensitive for HTML attributes

Author: RobinDev

src/Util/RegexHelper.php

@@ -42,7 +42,7 @@ final class RegexHelper
     public const PARTIAL_IN_PARENS_NOSP        = '\((' . self::PARTIAL_REG_CHAR . '|' . self::PARTIAL_ESCAPED_CHAR . '|\\\\)*\)';
     public const PARTIAL_TAGNAME               = '[a-z][a-z0-9-]*';
     public const PARTIAL_BLOCKTAGNAME          = '(?:address|article|aside|base|basefont|blockquote|body|caption|center|col|colgroup|dd|details|dialog|dir|div|dl|dt|fieldset|figcaption|figure|footer|form|frame|frameset|h1|head|header|hr|html|iframe|legend|li|link|main|menu|menuitem|nav|noframes|ol|optgroup|option|p|param|search|section|summary|table|tbody|td|tfoot|th|thead|title|tr|track|ul)';
-    public const PARTIAL_ATTRIBUTENAME         = '[a-z_:][a-z0-9:._-]*';
+    public const PARTIAL_ATTRIBUTENAME         = '[A-Za-z_:][A-Za-z0-9:._-]*';
     public const PARTIAL_UNQUOTEDVALUE         = '[^"\'=<>`\x00-\x20]+';
     public const PARTIAL_SINGLEQUOTEDVALUE     = '\'[^\']*\'';
     public const PARTIAL_DOUBLEQUOTEDVALUE     = '"[^"]*"';