Fix for SI-6245 with workaround for SI-2296.

protected/super accessor issue: Don't subvert the creation of the
standard protected accessor with the java interop accessor. For
SI-2296, the compiler emits an error instead of causing an illegal
access error at runtime.

Adapted from e498fac7fdbda3187a2a4fffcdf7fa4f9ddb7ac8.

Conflicts:

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

12 files changed, 37 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
index 2d6eee35a1..74e246e910 100644
--- a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala
@@ -241,6 +241,7 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
               && !sym.owner.isTrait
               && (sym.owner.enclosingPackageClass != currentPackage)
               && (qual.symbol.info.member(sym.name) ne NoSymbol)
+              && !needsProtectedAccessor(sym, tree.pos)
             )
             if (shouldEnsureAccessor) {
               log("Ensuring accessor for call to protected " + sym.fullLocationString + " from " + currentClass)
@@ -461,7 +462,15 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT
           )
         true
       }
-      isCandidate && !host.isPackageClass && !isSelfType 
+      def isJavaProtected = host.isTrait && sym.isJavaDefined && {
+        restrictionError(pos, unit,
+          """|%s accesses protected %s inside a concrete trait method.
+             |Add an accessor in a class extending %s as a workaround.""".stripMargin.format(
+                clazz, sym, sym.enclClass)
+        )
+        true
+      }
+      isCandidate && !host.isPackageClass && !isSelfType && !isJavaProtected
     }
 
     /** Return the innermost enclosing class C of referencingClass for which either
diff --git a/test/files/neg/t2296a.check b/test/files/neg/t2296a.check
new file mode 100644
index 0000000000..863b861046
--- /dev/null
+++ b/test/files/neg/t2296a.check
@@ -0,0 +1,5 @@
+S.scala:6: error: Implementation restriction: trait S accesses protected method foo inside a concrete trait method.
+Add an accessor in a class extending class J as a workaround.
+      foo()
+      ^
+one error found
diff --git a/test/files/run/t2296a/J.java b/test/files/neg/t2296a/J.java
index 78ff3e9804..78ff3e9804 100644
--- a/test/files/run/t2296a/J.java
+++ b/test/files/neg/t2296a/J.java
diff --git a/test/files/run/t2296a/S.scala b/test/files/neg/t2296a/S.scala
index 532d038a42..532d038a42 100644
--- a/test/files/run/t2296a/S.scala
+++ b/test/files/neg/t2296a/S.scala
diff --git a/test/files/neg/t2296b.check b/test/files/neg/t2296b.check
new file mode 100644
index 0000000000..07cc54d573
--- /dev/null
+++ b/test/files/neg/t2296b.check
@@ -0,0 +1,5 @@
+S_2.scala:6: error: Implementation restriction: trait S accesses protected method foo inside a concrete trait method.
+Add an accessor in a class extending class J_1 as a workaround.
+      foo()
+      ^
+one error found
diff --git a/test/files/run/t2296b/J_1.java b/test/files/neg/t2296b/J_1.java
index 4c91d47073..4c91d47073 100644
--- a/test/files/run/t2296b/J_1.java
+++ b/test/files/neg/t2296b/J_1.java
diff --git a/test/files/run/t2296b/S_2.scala b/test/files/neg/t2296b/S_2.scala
index 6cdb0cfaba..6cdb0cfaba 100644
--- a/test/files/run/t2296b/S_2.scala
+++ b/test/files/neg/t2296b/S_2.scala
diff --git a/test/files/pos/t6245/Base.java b/test/files/pos/t6245/Base.java
new file mode 100644
index 0000000000..651ea08bf2
--- /dev/null
+++ b/test/files/pos/t6245/Base.java
@@ -0,0 +1,5 @@
+package t1;
+
+public class Base {
+  protected Vis inner;
+}
diff --git a/test/files/pos/t6245/Foo.scala b/test/files/pos/t6245/Foo.scala
new file mode 100644
index 0000000000..f5f997fbff
--- /dev/null
+++ b/test/files/pos/t6245/Foo.scala
@@ -0,0 +1,9 @@
+import t1.Vis
+
+abstract class Foo extends t1.Base {
+  trait Nested {
+    def crash() {
+      inner
+    }
+  }
+}
diff --git a/test/files/pos/t6245/Vis.java b/test/files/pos/t6245/Vis.java
new file mode 100644
index 0000000000..4267f4e40b
--- /dev/null
+++ b/test/files/pos/t6245/Vis.java
@@ -0,0 +1,3 @@
+package t1;
+
+public class Vis { }
diff --git a/test/files/run/t2296a.check b/test/files/run/t2296a.check
deleted file mode 100644
index f75aec9d81..0000000000
--- a/test/files/run/t2296a.check
+++ /dev/null
@@ -1,2 +0,0 @@
-J.foo()
-J.foo()
diff --git a/test/files/run/t2296b.check b/test/files/run/t2296b.check
deleted file mode 100644
index f75aec9d81..0000000000
--- a/test/files/run/t2296b.check
+++ /dev/null
@@ -1,2 +0,0 @@
-J.foo()
-J.foo()