On Tue, 3 Oct 2023 at 21:35, Laurence Gonsalves <laure...@xenomachina.com> wrote: > > Thank you. My git bisect just found this change too. :-) > > We are processing documents that we have no control over, and some may use > these numeric encodings, so we can't update the documents. > > Looking at the XML spec > (https: //www.w3.org/TR/2008/REC-xml-20081126/#NT-EncName), it does say... > > EncName ::= [A-Za-z] ([A-Za-z0-9._] | '-')* > > ...and I assume that that's why the regex in XmlStreamReader was changed.
That would explain the somewhat convoluted RE. > However, the same part of the XML spec also says... > > > It is recommended that character encodings registered (as charsets) with the > > Internet Assigned Numbers Authority [IANA-CHARSETS], other than those just > > listed, be referred to using their registered names; other encodings should > > use names starting with an "x-" prefix. > > ...and "IANA-CHARSETS" links to > http://www.iana.org/assignments/character-sets/character-sets.xhtml > which has a table of character sets. In that table there are three columns of > possible codes for referring to charsets: "Preferred MIME", "Name", and > "Aliases". The "Aliases" column includes "437" (that's also where "cp437" can > be found). > > This seems like a bit of an inconsistency in the XML spec, as there are a > number of "Name" and "Alias" values that don't quite match the definition of > EncName. Indeed. There are also examples such as ISO_8859-1:1987 and ebcdic-de-273+euro > Given this inconsistency, and the fact that there are XML documents "in the > wild" that use these encoding names, would it be reasonable to relax the regex > just enough so that it'll work with these other names and aliases? I would say yes. I'm currently working on a test to check that all charsets *and aliases* can be matched, and on a fix to the RE. > > On Tue, Oct 3, 2023 at 12:24 PM sebb <seb...@gmail.com> wrote: > > > > Just had another look at the class: in 2.13, the regex for matching > > the encoding string was > > Pattern.compile("<\\?xml.*encoding[\\s]*=[\\s]*((?:\".[^\"]*\")|(?:'.[^']*'))", > > Pattern.MULTILINE); > > > > In 2.14, the pattern includes the following matching for the encoding: > > "encoding\\s*=\\s*((?:\"[A-Za-z]([A-Za-z0-9\\._]|-)*\")|(?:'[A-Za-z]([A-Za-z0-9\\\\._]|-)*'))", > > > > This does not allow for an encoding that starts with a digit; i.e. it > > won't match encoding='437' > > > > AFAICT, no supported encodings start with a digit. > > > > The '437' encoding is actually known as 'Cp437': > > https://docs.oracle.com/javase/8/docs/technotes/guides/intl/encoding.doc.html > > https://docs.oracle.com/en/java/javase/17/intl/supported-encodings.html > > > > Try using 'Cp437' as the encoding. > > > > On Tue, 3 Oct 2023 at 20:01, sebb <seb...@gmail.com> wrote: > > > > > > On Tue, 3 Oct 2023 at 18:05, Laurence Gonsalves > > > <laure...@xenomachina.com> wrote: > > > > > > > > On Tue, Oct 3, 2023 at 1:39 AM sebb <seb...@gmail.com> wrote: > > > > > > > > > > The byte input stream does not carry any encoding information, so the > > > > > XmlStreamReader has to guess what encoding was used. > > > > > > > > Determining what encoding to use when reading XML from a byte stream > > > > is the purpose of XmlStreamReader. From its documentation: "Character > > > > stream that handles all the necessary Voodoo to figure out the charset > > > > encoding of the XML document within the stream." > > > > > > > > What it's supposed to do in this case is use the "encoding='437'" from > > > > the input to determine that the Charset to use when decoding the byte > > > > stream is "437" (aka "code page 437"). > > > > > > Sorry, I completely overlooked that. > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: user-unsubscr...@commons.apache.org > > > > For additional commands, e-mail: user-h...@commons.apache.org > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: user-unsubscr...@commons.apache.org > > For additional commands, e-mail: user-h...@commons.apache.org > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@commons.apache.org > For additional commands, e-mail: user-h...@commons.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org
