zorba-coders team mailing list archive

[Dennis Knochenwefel <dennis.knochenwefel@xxxxxxxxxx>]

I'm not an encoding expert, so anything I say may potentially be wrong.

The string "\ud83d\udc4a" is an example containing a single javascript
escaped special character (cf http://www.charbase.com/1f44a-unicode-
fisted-hand-sign ). This is very common in JSON data as javascript
engines seem to use encodings utf-16 or ucs-2 internally.

I believe that the json parser attempts to parse "\ud83d\udc4a" as two
single utf-8 characters. As a result, it returns a string containing
invalid codepoints. This can be reproduced with the following query:

  import module namespace json = "http://www.zorba-xquery.com/modules/converters/json";;
  declare namespace j = "http://john.snelson.org.uk/parsing-json-into-xquery";;
  json:parse("{""text"":""Let's get it. \ud83d\udc4a""}")/j:pair[@name="text"]/text()

returns:

  dynamic error [err:FOCH0001]: "55357": 
  invalid code point; raised at runtime\zorba\src\api\serialization\serializer.cpp:204

Would it be possible for the json parser to detect utf-16 encoded
characters and convert them into valid utf-8 characters?

-- 
You received this bug notification because you are a member of Zorba
Coders, which is the registrant for Zorba.
https://bugs.launchpad.net/bugs/1024448

Title:
  data-converter module problems with non utf-8 characters

Status in Zorba - The XQuery Processor:
  Incomplete

Bug description:
  In public Json streams lots of non-utf8 character escapes can be found
  causing some problems when parsing json or tidying the contained html
  ( as for example marketed here: http://www.charbase.com/1f44a-unicode-
  fisted-hand-sign ).

  The following example Query causes a whole bunch of problems:

    import module namespace json = "http://www.zorba-xquery.com/modules/converters/json";;
    import module namespace html = "http://www.zorba-xquery.com/modules/converters/html";;
    declare namespace j = "http://john.snelson.org.uk/parsing-json-into-xquery";;
    let $text := "<p>" || json:parse("{""text"":""Let's get it. \ud83d\udc4a""}")/j:pair[@name="text"]/text() || "</p>"
    return html:parse($text)

  Problems:

  1. html:parse () has return type document-node(), but tries to return
  an empty-sequence in this example (discovered by ghislain)

  * --> moved to bug #1025194 *

  2. in file src/com/zorba-
  xquery/www/modules/converters/html.xq.src/tidy_wrapper.h function
  createHtmlItem(...) doesn't throw a proper error message (discovered
  by ghislain) which makes debugging really hard. In contrast, parse-xml
  throws a very helpful error:

    dynamic error [err:FODC0006]: invalid content passed to fn:parse-
  xml(): loader parsing error: Char 0xD83D out of allowed range;

  Could html:parse report the same error?

  * --> moved to bug #1025193 *

  3. json:parse() doesn't report an error here which is good in my
  opinion. Yet, as these utf-16 (?) encoded characters are used a lot in
  json, would it be possible to transform them into valid utf-8 (e.g.
  \ud83d\udc4a -> 👊)?

  Maybe these findings are going to be a problem in Jsoniq as well?

To manage notifications about this bug go to:
https://bugs.launchpad.net/zorba/+bug/1024448/+subscriptions