SI-4827 Test to demonstrate wrong position of constructor default arg

As demonstrated by the attached test, hyperlinking on constructor's
default arg doesn't work (the returned tree is the parameter tree,
i.e., `f`, which is of course wrong).

Printing the tree reveals the issue:

``
[[syntax trees at end of                     typer]] // Foo.scala
[0:63]package [0:0]<empty> {
  [0:37]class Baz extends [9:37][39]scala.AnyRef {
    [10:31]<paramaccessor> private[this] val f: [14]Int = _;
    [14]<stable> <accessor> <paramaccessor> def f: [14]Int = [14][14]Baz.this.f;
    [39]def <init>([14]f: [17]<type: [17]scala.Int> = [30]B.a): [9]Baz = [39]{
      [39][39][39]Baz.super.<init>();
      [9]()
    }
  };

  [6]<synthetic> object Baz extends [6][6]AnyRef {
    [6]def <init>(): [9]Baz.type = [6]{
      [6][6][6]Baz.super.<init>();
      [9]()
    };
    [14]<synthetic> def <init>$default$1: [14]Int = [30]B.a
  };
  [39:63]object B extends [48:63][63]scala.AnyRef {
    [63]def <init>(): [48]B.type = [63]{
      [63][63][63]B.super.<init>();
      [48]()
    };
    [52:61]private[this] val a: [56]Int = [60:61]2;
    [56]<stable> <accessor> def a: [56]Int = [56][56]B.this.a
  }
}
``

In short, the default argument in `<init>` (the constructor) has an
offset position, while we would expect it to have a range position.
Therefore, when locating a tree for any position between (start=) 10
and (end=) 31, the paramaccessor tree `f` is returned.

The next commit will correct the problem.

3 files changed, 19 insertions, 0 deletions

diff --git a/test/files/presentation/t4287.check b/test/files/presentation/t4287.check
new file mode 100644
index 0000000000..80c3e2fb23
--- /dev/null
+++ b/test/files/presentation/t4287.check
@@ -0,0 +1,11 @@
+reload: Foo.scala
+
+askHyperlinkPos for `f ` at (1,24) Foo.scala
+================================================================================
+[response] found askHyperlinkPos for `f ` at (1,15) Foo.scala
+================================================================================
+
+askHyperlinkPos for `f ` at (1,31) Foo.scala
+================================================================================
+[response] found askHyperlinkPos for `f ` at (1,15) Foo.scala
+================================================================================
diff --git a/test/files/presentation/t4287/Test.scala b/test/files/presentation/t4287/Test.scala
new file mode 100644
index 0000000000..bec1131c4c
--- /dev/null
+++ b/test/files/presentation/t4287/Test.scala
@@ -0,0 +1,3 @@
+import scala.tools.nsc.interactive.tests.InteractiveTest
+
+object Test extends InteractiveTest
\ No newline at end of file
diff --git a/test/files/presentation/t4287/src/Foo.scala b/test/files/presentation/t4287/src/Foo.scala
new file mode 100644
index 0000000000..a744eaabe2
--- /dev/null
+++ b/test/files/presentation/t4287/src/Foo.scala
@@ -0,0 +1,5 @@
+class Baz(val f: Int = B/*#*/.a/*#*/)
+
+object B {
+  val a = 2
+}