Inlined pattern matching won't unpickle

[OlivierBlanvillain]

object Test {
  @inline def f = "" match { case _ => false }

  def main(args: Array[String]): Unit = f
}

$ sbt "run -Ytest-pickler -Ystop-after:pickler /home/olivier/a.scala"
[...]
$ cat after-pickling.txt
[cannot display due to java.lang.AssertionError: assertion failed: Addr(134) Addr(138) Addr(140) MATCH, raw string = dotty.tools.dotc.printing.Formatting$StringFormatter@37f8bb67]

[liufengyun]

What's more fun is to remove the main method, which runs out of memory:

object Test {
  @inline def f = "" match { case _ => false }
}

As I'm working on tasty now, I'll look into it.

Edited: -Ytest-pickler only works with -Ystop-after:pickler.

[liufengyun]

The problem is that the pickling creates SHARED CaseDef for the inlined patmat:

    95:       DEFDEF(43) 23[main]
    98:         PARAMS(19)
   100:           PARAM(17) 24[args]
   103:             APPLIEDtpt(14)
   105:               IDENTtpt 25
   107:                 TYPEREF 25[Array]
   109:                   SHARED 93
   111:               IDENTtpt 19
   113:                 TYPEREF 19[String]
   115:                   TERMREF 26[Predef]
   117:                     SHARED 53
   119:         IDENTtpt 15
   121:           TYPEREF 15[Unit]
   123:             SHARED 93
   125:         BLOCK(13)
   127:           UNITconst
   128:           INLINED(10)
   130:             IDENTtpt 3
   132:               SHARED 10
   134:             MATCH(4)
   136:               SHARED 64                      <==  sharing of selector
   138:               SHARED 66                      <==  sharing of case def

However, the code doesn't handle shared CaseDef:

            case MATCH =>
              Match(readTerm(), readCases(end))       // <===   cases assumes no sharing!

The code for readCases:

    def readCases(end: Addr)(implicit ctx: Context): List[CaseDef] =
      collectWhile(nextByte == CASEDEF && currentAddr != end) { readCase()(ctx.fresh.setNewScope) }

I see two possible fixes:

1. In pickling, disable sharing of CaseDef
2. Support sharing of case def by changing Tasty format to also serialise the number of cases

Could you please advise @odersky @DarkDimius ?