Backend assertion when package & class names collide

[scabug]

Scalac 2.12 got an assertion failure compiling the following code snippet.
It seems to be a recent regression since scalac version 2.11.8 can compile the code.
The case is generated from an exsiting test program in the scala repository.

$ scalac -version
Scala compiler version 2.12.0-20161028-204919-0666377 -- Copyright 2002-2016, LAMP/EPFL and Lightbend, Inc.


$ scalac abc.scala
java.lang.AssertionError: assertion failed: List(Ltest/p/A;, Ltest/p/A$;)
	at scala.Predef$.assert(Predef.scala:219)
	at scala.tools.nsc.backend.jvm.BTypes$ClassBType.checkInfoConsistency(BTypes.scala:887)
	at scala.tools.nsc.backend.jvm.BTypes$ClassBType.info_$eq(BTypes.scala:859)
	at scala.tools.nsc.backend.jvm.BTypesFromSymbols.setClassInfo(BTypesFromSymbols.scala:446)
	at scala.tools.nsc.backend.jvm.BTypesFromSymbols.$anonfun$classBTypeFromSymbol$5(BTypesFromSymbols.scala:126)
	at scala.collection.MapLike.getOrElse(MapLike.scala:128)
	at scala.collection.MapLike.getOrElse$(MapLike.scala:126)
	at scala.collection.concurrent.TrieMap.getOrElse(TrieMap.scala:631)
	at scala.tools.nsc.backend.jvm.BTypesFromSymbols.classBTypeFromSymbol(BTypesFromSymbols.scala:118)
	at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.genPlainClass(BCodeSkelBuilder.scala:94)
	at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase$Worker1.visit(GenBCode.scala:190)
	at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase$Worker1.$anonfun$run$1(GenBCode.scala:139)
	at scala.tools.nsc.Global$GlobalPhase.withCurrentUnitNoLog(Global.scala:395)
	at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase$Worker1.run(GenBCode.scala:139)
	at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.buildAndSendToDisk(GenBCode.scala:381)
	at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.run(GenBCode.scala:350)
	at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1404)
	at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1389)
	at scala.tools.nsc.Global$Run.compileSources(Global.scala:1384)
	at scala.tools.nsc.Global$Run.compile(Global.scala:1478)
	at scala.tools.nsc.Driver.doCompile(Driver.scala:35)
	at scala.tools.nsc.MainClass.doCompile(Main.scala:24)
	at scala.tools.nsc.Driver.process(Driver.scala:55)
	at scala.tools.nsc.Driver.main(Driver.scala:68)
	at scala.tools.nsc.Main.main(Main.scala)
error: Error while emitting abc.scala
assertion failed: List(Ltest/p/A;, Ltest/p/A$;)
one error found



$ cat abc.scala
package test
package p { class A(a: String = "") }
package object po { type A = p.A }
import po._
class p { val a = new A() }

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-10014?orig=1
Reporter: Qirun Zhang (helloqirun)
Affected Versions: 2.12.0-RC2

[scabug]

@lrytz said:
This might be fixed by scala/scala#5482

[scabug]

Qirun Zhang (helloqirun) said:
I checked my scalac version, it is at

commit 066637781d42d8c512abaf7496e679e0e9f250e6
Merge: 4a487ca 795d59a
Author: Lukas Rytz <lukas.rytz@gmail.com>

I could still observe the assertion failure.

[scabug]

@lrytz said:
OK, thanks for checking.

[SethTisue]

Same crash in 2.13.12.

Scala 3.3.1 gives

-- [E161] Naming Error: S.scala:5:6 --------------------------------------------
5 |class p { val a = new A() }
  |^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |p is already defined as package test.p
1 error found

[som-snytt]

Let's see, I last visited this ticket on

Feb  8  2023 t10014.scala

Sorry, Seth, I ought to have commented.