POM XML formatter incorrectly adds newlines before CDATA sections

(This was originally filed as eclipse-m2e/m2e-core#1015, but I was told I need to file it with Eclipse Wild Web Developer.)

Using Eclipse 2022-09, I can add a CDATA section inside a Maven POM (pom.xml) property definition like this:

<properties>
    <test.cdata><![CDATA[<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
	<entry key="foo">bar</entry>
</properties>]]></test.cdata>
</properties>

The purpose is obvious: I don’t want to XML-encode all the XML delimiters in the value.

However when I format the file using Ctrl+Shift+F, Eclipse adds newlines and indents before and after the CDATA section:

<properties>
    <test.cdata>
      <![CDATA[<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
	<entry key="foo">bar</entry>
</properties>]]>
    </test.cdata>
<properties>

This corrupts the data! The whole point of using a CDATA section is that I wanted the exact content specified in a property. Now extra whitespace has been added in the value of the property. (It would have been worse to format inside the CDATA section, but this is still not good.)

I would guess the problem is that the formatting algorithm is treating CDATA sections as if they were XML DOM elements. That is, I understand that if I have this XML:

<foo><bar>…</bar></foo>

Then the XML formatter should format it to:

<foo>
  <bar>…</bar>
</foo>

However CDATA sections are not elements! Their purpose is merely to indicate whether content needs escaping or should be interpreted literally. They do not create a new element nesting context!!! They must be left along entirely; no newlines, whitespace, or anything else should be added, neither inside the CDATA section, before the CDATA section, nor after the CDATA section.

[angelozerr]

WWD should be updated to expose that setting. So https://github.com/eclipse/wildwebdeveloper/issues/941 still stands

@fbricon we would like to switch the experimental formatter as current formmater ASAP when it will supports all features from the current formatter. @JessicaJHee works hard on this topic and I think we are in the good way.

In other words WWD should not expose this setting which will disappear in few months.

[mickaelistria]

Thanks. I could reproduce the issue it in latest snapshots of Wild Web Developer. However, the problem is not “hosted” by Wild Web Developer itself but by the LemMinX language server that is used by Wild Web Developer to provide formatting (among other things). Now that you’re getting familiar with opening the same issue on multiple projects as investigation goes on, would you mind bringing this issue to https://github.com/eclipse/lemminx/issues 😉 I really believe it will be the final destination here.