SI-7232 Fix Java import vs defn. binding precendence

Java Spec:
> A single-type-import declaration d in a compilation unit c
> of package p that imports a type named n shadows, throughout
> c, the declarations of:
>   - any top level type named n declared in another compilation
>     unit of p
>   - any type named n imported by a type-import-on-demand
>     declaration in c
>   - any type named n imported by a static-import-on-demand
>     declaration in c

Scala Spec:
> Bindings of different kinds have a precedence defined on them:
>   1. Definitions and declarations that are local, inherited, or made
>      available by a package clause in the same compilation unit where
>      the definition occurs have highest precedence.
>   2. Explicit imports have next highest precedence.

This is a forward port of 6e79370, which did not merge cleanly
and was omitted in the regular merge from 2.10.x to master.

Conflicts:
	src/compiler/scala/tools/nsc/typechecker/Typers.scala

1 files changed, 7 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index e966cc9060..9bdf429dce 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -530,7 +530,13 @@ trait Namers extends MethodSynthesis {
           // Setting the position at the import means that if there is
           // more than one hidden name, the second will not be warned.
           // So it is the position of the actual hidden name.
-          checkNotRedundant(tree.pos withPoint fromPos, from, to)
+          //
+          // Note: java imports have precence over definitions in the same package
+          //       so don't warn for them. There is a corresponding special treatment
+          //       in the shadowing rules in typedIdent to (SI-7232). In any case,
+          //       we shouldn't be emitting warnings for .java source files.
+          if (!context.unit.isJava)
+            checkNotRedundant(tree.pos withPoint fromPos, from, to)
         }
       }