Protected protected constructors.

since r19547, which was for #1836 but loosened the noose too much.
Closes #4128, review by odersky.

3 files changed, 47 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index 7f0be68fca..0aeea8174a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -371,6 +371,7 @@ trait Contexts { self: Analyzer =>
      */
     def isAccessible(sym: Symbol, pre: Type, superAccess: Boolean): Boolean = {
       lastAccessCheckDetails = ""
+      // Console.println("isAccessible(%s, %s, %s)".format(sym, pre, superAccess))
 
       @inline def accessWithinLinked(ab: Symbol) = {
         val linked = ab.linkedClassOfClass
@@ -445,7 +446,6 @@ trait Contexts { self: Analyzer =>
         || sym.isProtected &&
              (  superAccess
              || pre.isInstanceOf[ThisType]
-             || sym.isConstructor
              || phase.erasedTypes
              || isProtectedAccessOK(sym)
              || (sym.allOverriddenSymbols exists isProtectedAccessOK)
diff --git a/test/files/neg/protected-constructors.check b/test/files/neg/protected-constructors.check
new file mode 100644
index 0000000000..d6b9221a49
--- /dev/null
+++ b/test/files/neg/protected-constructors.check
@@ -0,0 +1,25 @@
+protected-constructors.scala:17: error: too many arguments for constructor Foo1: ()dingus.Foo1
+    val foo1 = new Foo1("abc")
+               ^
+protected-constructors.scala:18: error: constructor Foo2 in class Foo2 cannot be accessed in object P
+ Access to protected constructor Foo2 not permitted because
+ enclosing class object P in package hungus is not a subclass of 
+ class Foo2 in package dingus where target is defined
+    val foo2 = new Foo2("abc")
+               ^
+protected-constructors.scala:19: error: class Foo3 in object Ding cannot be accessed in object dingus.Ding
+ Access to protected class Foo3 not permitted because
+ enclosing class object P in package hungus is not a subclass of 
+ object Ding in package dingus where target is defined
+    val foo3 = new Ding.Foo3("abc")
+                        ^
+protected-constructors.scala:15: error: class Foo3 in object Ding cannot be accessed in object dingus.Ding
+ Access to protected class Foo3 not permitted because
+ enclosing class object P in package hungus is not a subclass of 
+ object Ding in package dingus where target is defined
+    class Bar3 extends Ding.Foo3("abc")
+                            ^
+protected-constructors.scala:15: error: too many arguments for constructor Object: ()java.lang.Object
+    class Bar3 extends Ding.Foo3("abc")
+               ^
+5 errors found
diff --git a/test/files/neg/protected-constructors.scala b/test/files/neg/protected-constructors.scala
new file mode 100644
index 0000000000..2838caf09c
--- /dev/null
+++ b/test/files/neg/protected-constructors.scala
@@ -0,0 +1,21 @@
+package dingus {
+  class Foo1() { protected def this(name: String) = this() }
+  class Foo2 protected (name: String) { }
+  object Ding {
+    protected class Foo3(name: String) { }
+  }
+}
+
+package hungus {
+  import dingus._
+
+  object P {
+    class Bar1 extends Foo1("abc")
+    class Bar2 extends Foo2("abc")
+    class Bar3 extends Ding.Foo3("abc")
+
+    val foo1 = new Foo1("abc")
+    val foo2 = new Foo2("abc")
+    val foo3 = new Ding.Foo3("abc")
+  }
+}