6 files changed, 45 insertions, 0 deletions
diff --git a/test/files/neg/t5318.check b/test/files/neg/t5318.check
new file mode 100644
index 0000000000..d6a3a57935
--- /dev/null
+++ b/test/files/neg/t5318.check
@@ -0,0 +1,5 @@
+t5318.scala:7: error: diverging implicit expansion for type CompilerHang.this.TC[F]
+starting with method tc in class CompilerHang
+  breakage  // type checker doesn't terminate, should report inference failure
+  ^
+one error found
diff --git a/test/files/neg/t5318.scala b/test/files/neg/t5318.scala
new file mode 100644
index 0000000000..8009c66e6b
--- /dev/null
+++ b/test/files/neg/t5318.scala
@@ -0,0 +1,8 @@
+class CompilerHang {
+  trait TC[M[_]]
+  trait S[A]
+
+  implicit def tc[M[_]](implicit M0: TC[M]): TC[S] = null
+  def breakage[F[_] : TC] = 0
+  breakage  // type checker doesn't terminate, should report inference failure
+}
+\ No newline at end of file
diff --git a/test/files/neg/t5318b.check b/test/files/neg/t5318b.check
new file mode 100644
index 0000000000..47a10d6733
--- /dev/null
+++ b/test/files/neg/t5318b.check
@@ -0,0 +1,5 @@
+t5318b.scala:7: error: diverging implicit expansion for type DivergingImplicitReported.this.TC[F]
+starting with method tc in class DivergingImplicitReported
+  breakage // correct: diverging implicit expansion
+  ^
+one error found
+\ No newline at end of file
diff --git a/test/files/neg/t5318b.scala b/test/files/neg/t5318b.scala
new file mode 100644
index 0000000000..123f8b4e04
--- /dev/null
+++ b/test/files/neg/t5318b.scala
@@ -0,0 +1,8 @@
+class DivergingImplicitReported {
+  trait TC[M]
+  trait S
+
+  implicit def tc[M](implicit M0: TC[M]): TC[S] = null
+  def breakage[F: TC] = 0
+  breakage // correct: diverging implicit expansion
+}
+\ No newline at end of file
diff --git a/test/files/neg/t5318c.check b/test/files/neg/t5318c.check
new file mode 100644
index 0000000000..594539be69
--- /dev/null
+++ b/test/files/neg/t5318c.check
@@ -0,0 +1,5 @@
+t5318c.scala:13: error: diverging implicit expansion for type CompilerHang.this.TC[F]
+starting with method tc in class CompilerHang
+  breakage // type checker doesn't terminate, should report inference failure
+  ^
+one error found
diff --git a/test/files/neg/t5318c.scala b/test/files/neg/t5318c.scala
new file mode 100644
index 0000000000..477a9874ad
--- /dev/null
+++ b/test/files/neg/t5318c.scala
@@ -0,0 +1,14 @@
+class CompilerHang {
+  trait TC[M[_]]
+  trait S[A]
+
+  class C[M[_]] {
+    type TCM = TC[M]
+  }
+
+  // A nefarious implicit, to motivate the removal of `&& sym.owner.isTerm` from
+  // `isFreeTypeParamNoSkolem`.
+  implicit def tc[x[_], CC[x[_]] <: C[x]](implicit M0: CC[x]#TCM): CC[x]#TCM = null
+  def breakage[F[_] : TC] = 0
+  breakage // type checker doesn't terminate, should report inference failure
+}