SI-8029 Avoid multi-run cyclic error with companions, package object

The bug report suggests this problem only became visible in the
IDE *after* 2.10.3, but I tested an IDE with exactly 2.10.3 and
saw the same problem.

In fact, my test case fails as far back as 2.10.0. I suspect the
problem showed up after 816cecf9a9, which checks that pairs of
companion symbols are codefined eagerly in Namers.

This commit modifies the check of `rawInfo ne NoType`
in `isCoDefinedWith` to avoid triggering adaptation of types from
the previous run. I'm not sure of the precise intent of that check.
I looked at c9861cd198 (genesis of isCoDefinedWith). Before that we
get back to 3761cb4b3a1 (the dawn of Subversion.)

1 files changed, 57 insertions, 0 deletions

diff --git a/test/files/run/t8029.scala b/test/files/run/t8029.scala
new file mode 100644
index 0000000000..dbd5c41387
--- /dev/null
+++ b/test/files/run/t8029.scala
@@ -0,0 +1,57 @@
+import scala.tools.partest._
+import scala.tools.nsc._
+
+object Test extends DirectTest {
+
+  override def extraSettings: String = "-usejavacp -nowarn -Ystop-after:typer"
+
+  override def code = "" // not used
+
+  def code1 = """
+package object p1 {
+  trait A
+  object A
+}
+  """
+
+  def code2 = """
+package object p2 {
+  class A
+  object A
+}
+  """
+
+  def code3 = """
+package object p3 {
+  object A
+  trait A
+}
+  """
+
+  def code4 = """
+package object p4 {
+  object A
+  trait A
+}
+  """
+
+  def show() {
+    val global = newCompiler()
+    import global._
+    def typecheck(code: String): Unit = {
+      val r = new Run
+      val sourceFile = newSources(code).head
+      global.reporter.reset()
+      r.compileSources(sourceFile :: Nil)
+      assert(!global.reporter.hasErrors)
+    }
+
+    def typecheckTwice(code: String): Unit = {
+      typecheck(code)
+      typecheck(code)
+    }
+
+    // was: illegal cyclic reference involving package ...
+    Seq(code1, code2, code3, code4) foreach typecheckTwice
+  }
+}