SI-8085 Fix BrowserTraverser for package objects

A source file like:

    import foo.bar
    package object baz

Is parsed into:

    package <empty> {
       import foo.bar
       package baz {
          object `package`
       }
    }

A special case in Namers compensates by adjusting the owner of
`baz` to be `<root>`, rather than `<empty>`.

This wasn't being accounted for in `BrowserTraverser`, which
underpins `-sourcepath`, and allows the presentation compiler to
load top level symbols from sources outside those passes as
the list of sources to compile.

This bug did not appear in sources like:

    package p1
    package object p2 { ... }

... because the parser does not wrap this in the `package <empty> {}`

This goes some way to explaining why it has gone unnoticed for
so long.

4 files changed, 51 insertions, 0 deletions

diff --git a/test/files/presentation/t8085b/Test.scala b/test/files/presentation/t8085b/Test.scala
new file mode 100644
index 0000000000..e46b7ab8c8
--- /dev/null
+++ b/test/files/presentation/t8085b/Test.scala
@@ -0,0 +1,27 @@
+import scala.tools.nsc.interactive.tests.InteractiveTest
+import scala.reflect.internal.util.SourceFile
+import scala.tools.nsc.interactive.Response
+
+object Test extends InteractiveTest {
+
+  override def execute(): Unit = {
+    val src = loadSourceAndWaitUntilTypechecked("NodeScalaSuite.scala")
+    checkErrors(src)
+  }
+
+  private def loadSourceAndWaitUntilTypechecked(sourceName: String): SourceFile = {
+    val sourceFile = sourceFiles.find(_.file.name == sourceName).head
+    askReload(List(sourceFile)).get
+    askLoadedTyped(sourceFile).get
+    sourceFile
+  }
+
+  private def checkErrors(source: SourceFile): Unit = compiler.getUnitOf(source) match {
+    case Some(unit) =>
+      val problems = unit.problems.toList
+      if(problems.isEmpty) reporter.println("Test OK")
+      else problems.foreach(problem => reporter.println(problem.msg))
+
+    case None => reporter.println("No compilation unit found for " + source.file.name)
+  }
+}
diff --git a/test/files/presentation/t8085b/src/p1/nodescala/Foo.scala b/test/files/presentation/t8085b/src/p1/nodescala/Foo.scala
new file mode 100644
index 0000000000..8ed1ada6b6
--- /dev/null
+++ b/test/files/presentation/t8085b/src/p1/nodescala/Foo.scala
@@ -0,0 +1,4 @@
+package p1
+package nodescala
+
+class Foo
diff --git a/test/files/presentation/t8085b/src/p1/nodescala/NodeScalaSuite.scala b/test/files/presentation/t8085b/src/p1/nodescala/NodeScalaSuite.scala
new file mode 100644
index 0000000000..f6da67bdc7
--- /dev/null
+++ b/test/files/presentation/t8085b/src/p1/nodescala/NodeScalaSuite.scala
@@ -0,0 +1,11 @@
+package p1
+package nodescala
+
+class NodeScalaSuite {
+  "".rich
+
+  // This is here only to prove that the presentation compiler is instantiated with the
+  // correct `sourcepath` value (if it wasn't, you would see a `not found: type Foo` in
+  // the test's output
+  println(new Foo())
+}
diff --git a/test/files/presentation/t8085b/src/p1/nodescala/package.scala b/test/files/presentation/t8085b/src/p1/nodescala/package.scala
new file mode 100644
index 0000000000..cc383f1bab
--- /dev/null
+++ b/test/files/presentation/t8085b/src/p1/nodescala/package.scala
@@ -0,0 +1,9 @@
+import scala.Some // <-- if you move the import *inside* the package object, then it all works fine!!
+
+package p1 {
+  package object nodescala {
+    implicit class StringOps(val f: String) {
+      def rich = 0
+    }
+  }
+}