SI-8502 Rework handling of stub symbols in unpickler

  - Rework previous fixes for SI-8502 to move the creation of
    a term or type stub symbol during unpickling to the initial
    point of stub creation, based on the tag.
  - Just set the PACKAGE flag on class stub symbols created during
    unpickling `ThisType`, rather than bothering with a different
    subclass of `StubSymbol` for (assumed) packages.

2 files changed, 4 insertions, 6 deletions

diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 56b6dc078d..6a7b3fc9a2 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -488,7 +488,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
      *  often to the point of never.
      */
     def newStubSymbol(name: Name, missingMessage: String, isPackage: Boolean = false): Symbol = name match {
-      case n: TypeName  => if (isPackage) new StubPackageClassSymbol(this, n, missingMessage) else new StubClassSymbol(this, n, missingMessage)
+      case n: TypeName  => new StubClassSymbol(this, n, missingMessage)
       case _            => new StubTermSymbol(this, name.toTermName, missingMessage)
     }
 
@@ -3423,7 +3423,6 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     override def companionSymbol = fail(NoSymbol)
   }
   class StubClassSymbol(owner0: Symbol, name0: TypeName, val missingMessage: String) extends ClassSymbol(owner0, owner0.pos, name0) with StubSymbol
-  class StubPackageClassSymbol(owner0: Symbol, name0: TypeName, val missingMessage: String) extends PackageClassSymbol(owner0, owner0.pos, name0) with StubSymbol
   class StubTermSymbol(owner0: Symbol, name0: TermName, val missingMessage: String) extends TermSymbol(owner0, owner0.pos, name0) with StubSymbol
 
   trait FreeSymbol extends Symbol {
diff --git a/src/reflect/scala/reflect/internal/pickling/UnPickler.scala b/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
index 6dea184826..3bc845557f 100644
--- a/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
+++ b/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
@@ -267,7 +267,8 @@ abstract class UnPickler {
                       |because it (or its dependencies) are missing. Check your build definition for
                       |missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
                       |A full rebuild may help if '$filename' was compiled against an incompatible version of ${owner.fullName}.$advice""".stripMargin
-                owner.newStubSymbol(name, missingMessage)
+                val stubName = if (tag == EXTref) name else name.toTypeName
+                owner.newStubSymbol(stubName, missingMessage)
               }
             }
           }
@@ -392,9 +393,7 @@ abstract class UnPickler {
 
       def readThisType(): Type = {
         val sym = readSymbolRef() match {
-          case stub: StubSymbol if !stub.isClass =>
-            // SI-8502 This allows us to create a stub for a unpickled reference to `missingPackage.Foo`.
-            stub.owner.newStubSymbol(stub.name.toTypeName, stub.missingMessage, isPackage = true)
+          case stub: StubSymbol => stub.setFlag(PACKAGE)
           case sym => sym
         }
         ThisType(sym)