"Unexpected tree in genLoad" compiler crash when invoking super on java method of class with package access

[scabug]

When trying to invoke a super method from java base class I got a very strange error:

Unexpected tree in genLoad: Worker.super/class scala.reflect.api.Trees$Super at: source-..\Worker.scala,line-9,offset=130

while compiling:  Worker.scala
current phase:  icode
library version:  version 2.10.0-20120406-151649-1a6408c429
compiler version:  version 2.10.0-20120406-151649-1a6408c429
uncaught exception during compilation: scala.reflect.internal.FatalError
 scala.reflect.internal.Fatal
Unexpected tree in genLoad: Worker.super/class scala.reflect.api.Trees$Super at: source-...\Worker.scala,line-9,offset=130
at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:40)
at scala.tools.nsc.Global.abort(Global.scala:191)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.scala$tools$nsc$backend$icode$GenICode$ICodePhase$$genLoad(GenICode.scala:1105)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.genLoadQualifier(GenICode.scala:1150)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.scala$tools$nsc$backend$icode$GenICode$ICodePhase$$genLoad(GenICode.scala:721)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.scala$tools$nsc$backend$icode$GenICode$ICodePhase$$genLoad(GenICode.scala:901)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:115)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase$$anonfun$gen$1.apply(GenICode.scala:71)
at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)
at scala.collection.immutable.List.foreach(List.scala:77)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:71)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:140)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:90)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:81)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.gen(GenICode.scala:67)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.apply(GenICode.scala:63)
at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:421)
at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:387)
at scala.tools.nsc.Global$GlobalPhase$$anonfun$run$1.apply(Global.scala:381)
at scala.collection.Iterator$class.foreach(Iterator.scala:697)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1124)
at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:381)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.run(GenICode.scala:56)
at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1303)
at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1276)
at scala.tools.nsc.Global$Run.compileSources(Global.scala:1270)
at scala.tools.nsc.Global$Run.compile(Global.scala:1403)
at scala.tools.nsc.Driver.doCompile(Driver.scala:31)
at scala.tools.nsc.Main$.doCompile(Main.scala:81)
at scala.tools.nsc.Driver.process(Driver.scala:52)
at scala.tools.nsc.Driver.main(Driver.scala:65)
at scala.tools.nsc.Main.main(Main.scala)

Finally I was able to reproduce this case. The problem arise when you override a method in base class hierarchy
where class which defines a given method has a package access modifier.

Here a example:

//base abstract public class

package com.test;

public abstract class Base {

}

//class in the middle of the inheritance chain that has a package wide access

package com.test;

class Middle extends Base {
    public void doSomething() {
        System.out.println("You just called a base class!");
    }
}

//a public class that inherits from a previous class

package com.test;

public class Top extends Middle {

}

//a scala class that inherits from a public class but overrides a method defined in class with default access

import com.test.Top

class Worker extends Top {

  override def doSomething() {
    super.doSomething()
  }

}

Of course this case should be rare in practice but at least the compiler should not crash on this.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-5650?orig=1
Reporter: Aliaksandr Zhuhrou (zhygr)
Affected Versions: 2.10.0
Duplicates #4626

[scabug]

Aliaksandr Zhuhrou (zhygr) said:
Also the related problem that you may actually override a inaccessible method and in you don't call super the compiler say you nothing.
But in the end you get an IllegalAccessException.
Example

import com.test.Top

class Worker extends Top {

override def doSomething() { System.out.println("Hm. It works.") }

}

In this case my intuition says that compiler should also give you a meanfull error.

[scabug]

@magarciaEPFL said:
Workaround (and probably the most sensible design, anyway)

package com.test

class Worker extends Top {
  . . . 

[scabug]

@paulp said:
This is a duplicate of #4626.