Build manager incorrectly reports errors against inherited Java inner classes when using -make:...

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I suspect this is related to #3133 which showed similar symptoms. Say you have a pair of Java classes:

public class Base {
  public class Inner {}
}

public class Derived extends Base {
  public void foo(Inner i) {}
}

If you run scalac on them with any -make recompilation strategy other than all, it complains:

$$ ~/scala/scala-2.8.0.RC1/bin/scalac -make:changed *.java
Derived.java:2: error: not found: type Inner
  public void foo(Inner i) {}
                  ^
one error found

This happens if a method in the derived class takes or returns an instance of the inner class, but not if it merely has a field of the inner type.

With -make:all or no -make option at all, scalac is happy.

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Imported From: https://issues.scala-lang.org/browse/SI-3347?orig=1
Reporter: rjm

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@harrah said:
I don't see the error in 2.8.0.RC1 or r21666:

$$ scala-2.8.0.RC1/bin/scalac -make:changed *.java
$$ scala-2.8.0.RC1/bin/scalac -make:changed *.java
Recompiling 2 files
$$ scala-2.8.0.RC1/bin/scalac -make:changed *.java
Recompiling 2 files
$$

It might be a problem that the Java files are always recompiled, but that is a separate issue.

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rjm said:
This definitely happens for me in both RC1 and the latest nightly (r21659 as I type) on both my development machines. What could be in the environment that would influence this? I've tried with both the standard Sun Java 6 and the OpenJDK Java 6 that Debian packages, with the same result.

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rjm said:
Ok, I know why it works for you. It's a copy fail on my part, the inner class needs to be static for the problem to trigger, in RC1 or the latest nightly:

public class Base {
  public static class Inner {}
}

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@hubertp said:
One workaround for this problem is to explicitly tell the compiler the type of i to be B.Inner. This then compiles for both, javac and scalac.

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rjm said:
True, though not terribly helpful when dealing with a large, actively developed Java codebase that you're trying to introduce a Scala subsystem into. The Java devs will push back against that; not using -make:{something} at all is a better workaround in my current situation.

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@hubertp said:
I think #1409 seems to be the main reason for this problem. I know it compiles when you just write

scalac src/B.java src/F.java

but doesn't work for dependency management because it parses the symbols and their types (and it doesn't know the type of Inner but knows of B.Inner). Because of #1409, even if you have just src/B.java and some Scala class that uses the nested static class then you will get type error from the usual compiler (that doesn't happen with full names but I realize that's a workaround far from perfect).

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@hubertp said:
refined build manager is deprecated. bugs related to it will no longer be fixed.