fixes after rebase

Author: Florian3k

compiler/src/dotty/tools/dotc/core/SymbolLoaders.scala

@@ -418,18 +418,16 @@ class ClassfileLoader(val classfile: AbstractFile) extends SymbolLoader {
 }
 
 class TastyLoader(val tastyFile: AbstractFile) extends SymbolLoader {
-
+  val isBestEffortTasty = tastyFile.extension == "betasty"
   private val unpickler: tasty.DottyUnpickler =
     handleUnpicklingExceptions:
       val tastyBytes = tastyFile.toByteArray
-      new tasty.DottyUnpickler(tastyFile, tastyBytes) // reads header and name table
+      new tasty.DottyUnpickler(tastyFile, tastyBytes, isBestEffortTasty) // reads header and name table
 
   val compilationUnitInfo: CompilationUnitInfo | Null = unpickler.compilationUnitInfo
 
-  val isBestEffortTasty = tastyFile.name.endsWith(".betasty")
-
   def description(using Context): String =
-    if tastyFile.extension == ".betasty" then "Best Effort TASTy file " + tastyFile.toString
+    if isBestEffortTasty then "Best Effort TASTy file " + tastyFile.toString
     else "TASTy file " + tastyFile.toString
 
   override def doComplete(root: SymDenotation)(using Context): Unit =

compiler/src/dotty/tools/dotc/core/tasty/TastyUnpickler.scala

@@ -2,10 +2,11 @@ package dotty.tools.dotc
 package core
 package tasty
 
+import java.util.UUID
 import scala.language.unsafeNulls
 
 import dotty.tools.tasty.{TastyFormat, TastyVersion, TastyBuffer, TastyReader, TastyHeaderUnpickler, UnpicklerConfig}
-import dotty.tools.tasty.besteffort.BestEffortTastyHeaderUnpickler
+import dotty.tools.tasty.besteffort.{BestEffortTastyHeader, BestEffortTastyHeaderUnpickler}
 
 import TastyFormat.NameTags.*, TastyFormat.nameTagToString
 import TastyBuffer.NameRef
@@ -16,6 +17,18 @@ import NameKinds.*
 import dotty.tools.tasty.TastyHeader
 import dotty.tools.tasty.TastyBuffer.Addr
 
+case class CommonTastyHeader(
+  uuid: UUID,
+  majorVersion: Int,
+  minorVersion: Int,
+  experimentalVersion: Int,
+  toolingVersion: String
+):
+  def this(h: TastyHeader) =
+    this(h.uuid, h.majorVersion, h.minorVersion, h.experimentalVersion, h.toolingVersion)
+  def this(h: BestEffortTastyHeader) =
+    this(h.uuid, h.majorVersion, h.minorVersion, h.experimentalVersion, h.toolingVersion)
+
 object TastyUnpickler {
 
   abstract class SectionUnpickler[R](val name: String) {
@@ -126,9 +139,11 @@ class TastyUnpickler(protected val reader: TastyReader, isBestEffortTasty: Boole
     result
   }
 
-  val header =
-    if isBestEffortTasty then new BestEffortTastyHeaderUnpickler(scala3CompilerConfig, reader).readFullHeader()
-    else new TastyHeaderUnpickler(reader).readFullHeader()
+  val header: CommonTastyHeader =
+    if isBestEffortTasty then
+      new CommonTastyHeader(new BestEffortTastyHeaderUnpickler(scala3CompilerConfig, reader).readFullHeader())
+    else
+      new CommonTastyHeader(new TastyHeaderUnpickler(reader).readFullHeader())
 
   def readNames(): Unit =
     until(readEnd()) { nameAtRef.add(readNameContents()) }

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -447,6 +447,9 @@ class TreeUnpickler(reader: TastyReader,
               }
             case FLEXIBLEtype =>
               FlexibleType(readType())
+            case _ if isBestEffortTasty =>
+              goto(end)
+              new PreviousErrorType
           }
         assert(currentAddr == end, s"$start $currentAddr $end ${astTagToString(tag)}")
         result

compiler/test/dotc/neg-best-effort-pickling.blacklist

@@ -10,6 +10,9 @@ i6796.scala
 i14013.scala
 toplevel-cyclic
 curried-dependent-ift.scala
+i17121.scala
+illegal-match-types.scala
+i13780-1.scala
 
 # semantic db generation fails in the first compilation
 i1642.scala