Merge pull request #562 from retronym/ticket/5803

A band-aid solution for SI-5803.

3 files changed, 10 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/Trees.scala b/src/compiler/scala/tools/nsc/ast/Trees.scala
index 4c509778e9..1b8fe9a91a 100644
--- a/src/compiler/scala/tools/nsc/ast/Trees.scala
+++ b/src/compiler/scala/tools/nsc/ast/Trees.scala
@@ -362,7 +362,8 @@ trait Trees extends reflect.internal.Trees { self: Global =>
       }
 
       val x1 = new Transformer().transform(x)
-      assert(x.getClass isInstance x1, x1.getClass)
+      // The loose invariant is a temporary workaround for SI-5803
+      assert(x.getClass.isInstance(x1) || (x.isInstanceOf[ApplyConstructor] && x1.isInstanceOf[Apply]), (x.getClass, x1.getClass))
       x1.asInstanceOf[T]
     }
   }
diff --git a/test/files/neg/t5803.check b/test/files/neg/t5803.check
new file mode 100644
index 0000000000..6a2de2e1df
--- /dev/null
+++ b/test/files/neg/t5803.check
@@ -0,0 +1,4 @@
+t5803.scala:3: error: could not find implicit value for parameter ev: Nothing
+  new Foo(): String
+  ^
+one error found
diff --git a/test/files/neg/t5803.scala b/test/files/neg/t5803.scala
new file mode 100644
index 0000000000..f818272f86
--- /dev/null
+++ b/test/files/neg/t5803.scala
@@ -0,0 +1,4 @@
+object Test {
+  class Foo()(implicit ev: Nothing)
+  new Foo(): String
+}