[nomaster] SI-7166 catches DivergentImplicit in c.inferImplicitXXX

Despite inferImplicit usually being nice and buffering errors, apparently
it can also throw DivergentImplicit exception. This patch catches it and
only reports it if silent is set to false.

NOTE: we no longer have the DivergentImplicit exception in master,
so this commit only makes sense in 2.10.x.

3 files changed, 33 insertions, 0 deletions

diff --git a/test/files/neg/t7166.check b/test/files/neg/t7166.check
new file mode 100644
index 0000000000..c87198cb27
--- /dev/null
+++ b/test/files/neg/t7166.check
@@ -0,0 +1,4 @@
+Test_2.scala:2: error: silent = true does work!
+  println(implicitly[Complex[Foo]])
+                    ^
+one error found
diff --git a/test/files/neg/t7166/Impls_Macros_1.scala b/test/files/neg/t7166/Impls_Macros_1.scala
new file mode 100644
index 0000000000..62a15657c3
--- /dev/null
+++ b/test/files/neg/t7166/Impls_Macros_1.scala
@@ -0,0 +1,26 @@
+import scala.reflect.macros.Context
+import language.experimental.macros
+
+trait Complex[T]
+
+class Foo
+
+object Complex {
+  def impl[T: c.WeakTypeTag](c: Context): c.Expr[Complex[T]] = {
+    import c.universe._
+    def shout(msg: String) = {
+      val cannotShutMeUp = c.asInstanceOf[scala.reflect.macros.runtime.Context].universe.currentRun.currentUnit.error _
+      cannotShutMeUp(c.enclosingPosition.asInstanceOf[scala.reflect.internal.util.Position], msg)
+    }
+    try {
+      val complexOfT = appliedType(typeOf[Complex[_]], List(weakTypeOf[T]))
+      val infiniteRecursion = c.inferImplicitValue(complexOfT, silent = true)
+      shout("silent = true does work!")
+    } catch {
+      case ex: Exception => shout(ex.toString)
+    }
+    c.literalNull
+  }
+
+  implicit def genComplex[T]: Complex[T] = macro impl[T]
+}
diff --git a/test/files/neg/t7166/Test_2.scala b/test/files/neg/t7166/Test_2.scala
new file mode 100644
index 0000000000..dcc4593335
--- /dev/null
+++ b/test/files/neg/t7166/Test_2.scala
@@ -0,0 +1,3 @@
+object Test extends App {
+  println(implicitly[Complex[Foo]])
+}
\ No newline at end of file