Crash related to XML in given

Compiler version

3.0.0, 3.1.0, 3.1.2, 3.2.0-RC1

Minimized code

libraryDependencies += "org.scala-lang.modules" %% "scala-xml" % "2.1.0"

trait Renderer[A]:
  def render(x: A): xml.Elem

given Renderer[Int] with
  def render(x: Int) = <td>{ x.toString }</td>

Output (click arrow to expand)

error while checking  extends Renderer[Int] {
  def render(x: Int) =
    {
      {
        new _root_.scala.xml.Elem(null, "td", _root_.scala.xml.Null, $scope,
          false
        ,
          {
            val $buf = new _root_.scala.xml.NodeBuffer()
            $buf.&+(
              {
                x.toString
              }
            )
            $buf
          }*
        )
      }
    }
}

[som-snytt]

The off-by-one span error on Windows suggests maybe lineSeparator is involved, as it adds a CR to NL?

It works for me under WSL Ubuntu; I’m much too lazy to try it under bare Windows. Or rather, my instinct for self-preservation is just strong enough.

(For other newbies, I see the position check at parser is compile-time true, not a compiler option.)

[som-snytt]

The problem seems to be https://github.com/lampepfl/dotty/pull/15635/files#diff-052bd0d14090dbcf9a970757f11efe267009ee324696dcc3ea785c32eafc770cR77

which is corrected in https://github.com/lampepfl/dotty/pull/15635

It looks like the scala 2 fixes to locate the start of the element are simplified in scala 3, which tracks lastCharOffset.

This would be an example of unfortunate duplicative effort. How many versions of CharArrayReader does one need?

Another divergence is due to \u unicode escape handling. If diffing and porting, it’s nicer for diffs to remain small; the gold standard is still just to share utility code.