SI-7848 Xlint says what looks interpolated

The motivating use case was an Expecty debug string
getting flagged for `$eq`.

The test case demonstrates a different bug, in which
the position of the literal tree is changed when typer
gets rid of the unused local, so that when the tree is
re-typed in erasure, a second, spurious warning is
emitted at the start of the method. Specifically, the
second warning is not suppressed because of the
different position.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/files/neg/t7848-interp-warn.scala b/test/files/neg/t7848-interp-warn.scala
new file mode 100644
index 0000000000..bb3eeff60c
--- /dev/null
+++ b/test/files/neg/t7848-interp-warn.scala
@@ -0,0 +1,13 @@
+
+package test
+
+object Test {
+  def f = {
+    val foo = "bar"
+    "An important $foo message!"
+  }
+  def g = {
+    val foo = "bar"
+    "A doubly important ${foo * 2} message!"
+  }
+}