Merge pull request scala#592 from retronym/ticket/4975

Consider method-scoped companions in the implicit scope.

Author: Adriaan Moors

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

@@ -933,7 +933,7 @@ trait Implicits {
               }
             case None =>
               if (pre.isStable) {
-                val companion = sym.companionModule
+                val companion = companionSymbolOf(sym, context)
                 companion.moduleClass match {
                   case mc: ModuleClassSymbol =>
                     val infos =

test/files/pos/t4975.scala

@@ -0,0 +1,12 @@
+object ImplicitScope {
+  class A[T]
+
+  def foo {
+    trait B
+    object B {
+      implicit def ab = new A[B]
+    }
+
+    implicitly[A[B]]  // Error
+  }
+}