Merge pull request #2428 from hubertp/issue/7291

SI-7291: Don't throw exceptions while encountering diverging expansion.

4 files changed, 32 insertions, 6 deletions

diff --git a/test/files/neg/t696.check b/test/files/neg/t696.check
index ac26a864a5..b7bc5cdf98 100644
--- a/test/files/neg/t696.check
+++ b/test/files/neg/t696.check
@@ -1,5 +1,9 @@
-t696.scala:4: error: diverging implicit expansion for type TypeUtil0.Type[Any]
+t696.scala:5: error: diverging implicit expansion for type TypeUtil0.Type[Any]
 starting with method WithType in object TypeUtil0
-  as[Any](null);
+  as[Any](null)
          ^
-one error found
+t696.scala:6: error: diverging implicit expansion for type TypeUtil0.Type[X]
+starting with method WithType in object TypeUtil0
+  def foo[X]() = as[X](null)
+                      ^
+two errors found
diff --git a/test/files/neg/t696.scala b/test/files/neg/t696.scala
index a06a32141a..ca76f7ef6c 100644
--- a/test/files/neg/t696.scala
+++ b/test/files/neg/t696.scala
@@ -1,6 +1,7 @@
 object TypeUtil0 {
-  trait Type[+T];
+  trait Type[+T]
   implicit def WithType[S,T](implicit tpeS : Type[S], tpeT : Type[T]) : Type[S with T] = null
-  as[Any](null);
-  def as[T](x : Any)(implicit tpe : Type[T]) = null;
+  def as[T](x : Any)(implicit tpe : Type[T]) = null
+  as[Any](null)
+  def foo[X]() = as[X](null)
 }
diff --git a/test/files/run/t7291.check b/test/files/run/t7291.check
new file mode 100644
index 0000000000..c07ba986a3
--- /dev/null
+++ b/test/files/run/t7291.check
@@ -0,0 +1,2 @@
+conjure
+traversable
diff --git a/test/files/run/t7291.scala b/test/files/run/t7291.scala
new file mode 100644
index 0000000000..30c4261a81
--- /dev/null
+++ b/test/files/run/t7291.scala
@@ -0,0 +1,19 @@
+trait Fooable[T]
+object Fooable {
+  implicit def conjure[T]: Fooable[T] = {
+    println("conjure")
+    new Fooable[T]{}
+  }
+
+}
+
+object Test {
+  implicit def traversable[T, Coll[_] <: Traversable[_]](implicit
+elem: Fooable[T]): Fooable[Coll[T]] = {
+    println("traversable")
+    new Fooable[Coll[T]]{}
+  }
+  def main(args: Array[String]) {
+    implicitly[Fooable[List[Any]]] 
+  }
+}