In jdk/src/java.base/unix/classes/sun/nio/fs/MimeTypesFileTypeDetector.java there are two regexps:
String extRegex = "\\b" + EXTEQUAL +
"(\"[\\p{Graph}|\\p{Blank}]+?\"|\\p{Graph}+\\b)";
String[] extList = exts.split("[\\p{Blank}|\\p{Punct}]+");
which have redundant bar-character in the char class.