The eagerly awaited companion commit to r23622, the surprise hit

of last winter.  Singletons now have the singleton type inferred in
monomorphic contexts as well.  In english:

  scala> object X
  defined module X

  scala> def f = X
  f: X.type

Wait, that's not english.  English review by moors.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@25051 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/compiler/scala/tools/nsc/typechecker/Infer.scala

@@ -572,7 +572,7 @@ trait Infer {
           tparam -> Some(
             if      (targ.typeSymbol == RepeatedParamClass)     targ.baseType(SeqClass)
             else if (targ.typeSymbol == JavaRepeatedParamClass) targ.baseType(ArrayClass)
-            else if (targ.typeSymbol.isModuleClass) targ  // this infers Foo.type instead of "object Foo"
+            else if (targ.typeSymbol.isModuleClass) targ  // this infers Foo.type instead of "object Foo" (see also widenIfNecessary)
             else targ.widen
           )
         }

src/compiler/scala/tools/nsc/typechecker/Namers.scala

@@ -630,9 +630,14 @@ trait Namers { self: Analyzer =>
         case _ =>
           false
       }
+
       val tpe1 = tpe.deconst
       val tpe2 = tpe1.widen
-      if (sym.isVariable || sym.isMethod && !sym.hasAccessorFlag)
+
+      // This infers Foo.type instead of "object Foo"
+      // See Infer#adjustTypeArgs for the polymorphic case.
+      if (tpe.typeSymbolDirect.isModuleClass) tpe1
+      else if (sym.isVariable || sym.isMethod && !sym.hasAccessorFlag)
         if (tpe2 <:< pt) tpe2 else tpe1
       else if (isHidden(tpe)) tpe2
       // In an attempt to make pattern matches involving method local vals

test/files/jvm/interpreter.check

@@ -370,5 +370,5 @@ plusOne: (x: Int)Int
 res0: Int = 6
 res1: java.lang.String = after reset
 <console>:8: error: not found: value plusOne
-       plusOne(5) // should be undefined now
-       ^
+              plusOne(5) // should be undefined now
+              ^

test/files/neg/t3507.check

@@ -1,4 +1,4 @@
-t3507.scala:13: error: No Manifest available for object _1.b.c.
+t3507.scala:13: error: No Manifest available for _1.b.c.type.
   mani/*[object _1.b.c]*/(c) // kaboom in manifestOfType / TreeGen.mkAttributedQualifier
                          ^
 one error found