Closes #4457. Review by odersky

6 files changed, 115 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index fd27f178ef..0b1a9f6187 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -1568,7 +1568,9 @@ trait Infer {
                 (alts map pre.memberType) +", argtpes = "+ argtpes +", pt = "+ pt)
 
           var allApplicable = alts filter (alt =>
-            isApplicable(undetparams, followApply(pre.memberType(alt)), argtpes, pt))
+            // TODO: this will need to be re-written once we substitute throwing exceptions
+            // with generating error trees. We wrap this applicability in try/catch because of #4457.
+            try {isApplicable(undetparams, followApply(pre.memberType(alt)), argtpes, pt)} catch {case _: TypeError => false})
 
           //log("applicable: "+ (allApplicable map pre.memberType))
 
diff --git a/test/files/neg/t4457_1.check b/test/files/neg/t4457_1.check
new file mode 100644
index 0000000000..c6b83c6ce5
--- /dev/null
+++ b/test/files/neg/t4457_1.check
@@ -0,0 +1,7 @@
+t4457_1.scala:27: error: ambiguous reference to overloaded definition,
+both method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NZ[A])ImplicitConvAmbiguity2.AA[Float]
+and  method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NE[A])ImplicitConvAmbiguity2.AA[A]
+match argument types (Float)
+    val x = aFunc(4F)
+            ^
+one error found
diff --git a/test/files/neg/t4457_1.scala b/test/files/neg/t4457_1.scala
new file mode 100644
index 0000000000..11f12379f6
--- /dev/null
+++ b/test/files/neg/t4457_1.scala
@@ -0,0 +1,33 @@
+object ImplicitConvAmbiguity2 {
+
+  class N[T]
+  class NE[T] extends N[T]
+  class NN[T] extends N[T]
+  class NQ[T] extends N[T]
+  class NZ[T] extends N[T]
+  class AA[A]
+  class BB[A]
+
+  implicit def conv1(i: Float) = new NE[Float]
+  implicit def conv3(op: AA[java.util.TooManyListenersException]) = new N[java.util.TooManyListenersException]
+  implicit def conv4(op: AA[Float]) = new N[Float]
+  implicit def conv7(i: Float) = new NZ[Float]
+  implicit def conv5(e: BB[java.util.GregorianCalendar]) = new N[java.util.GregorianCalendar]
+
+  // These two will be in conflict in typeMe1
+  def aFunc[A](a: NE[A]) = new AA[A]
+  def aFunc[A](a: NZ[A]) = new AA[Float]
+
+  def aFunc[A](a: NN[A]) = new BB[A]
+  def aFunc[A](a: NQ[A]) = new BB[A]
+
+  def bFunc[T](e1: N[T]) = {}
+
+  def typeMe1 {
+    val x = aFunc(4F)
+    bFunc(x)
+  }
+  def typeMe2 {
+    bFunc(aFunc(4F))
+  }
+}
diff --git a/test/files/neg/t4457_2.check b/test/files/neg/t4457_2.check
new file mode 100644
index 0000000000..770a355395
--- /dev/null
+++ b/test/files/neg/t4457_2.check
@@ -0,0 +1,13 @@
+t4457_2.scala:27: error: ambiguous reference to overloaded definition,
+both method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NZ[A])ImplicitConvAmbiguity2.AA[A]
+and  method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NE[A])ImplicitConvAmbiguity2.AA[A]
+match argument types (Float)
+    val x = aFunc(4F)
+            ^
+t4457_2.scala:31: error: ambiguous reference to overloaded definition,
+both method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NZ[A])ImplicitConvAmbiguity2.AA[A]
+and  method aFunc in object ImplicitConvAmbiguity2 of type [A](a: ImplicitConvAmbiguity2.NE[A])ImplicitConvAmbiguity2.AA[A]
+match argument types (Float)
+    bFunc(aFunc(4F))
+          ^
+two errors found
diff --git a/test/files/neg/t4457_2.scala b/test/files/neg/t4457_2.scala
new file mode 100644
index 0000000000..f3a170f1f2
--- /dev/null
+++ b/test/files/neg/t4457_2.scala
@@ -0,0 +1,33 @@
+object ImplicitConvAmbiguity2 {
+
+  class N[T]
+  class NE[T] extends N[T]
+  class NN[T] extends N[T]
+  class NQ[T] extends N[T]
+  class NZ[T] extends N[T]
+  class AA[A]
+  class BB[A]
+
+  implicit def conv1(i: Float) = new NE[Float]
+  implicit def conv3(op: AA[java.util.TooManyListenersException]) = new N[java.util.TooManyListenersException]
+  implicit def conv4(op: AA[Float]) = new N[Float]
+  implicit def conv7(i: Float) = new NZ[Float]
+  implicit def conv5(e: BB[java.util.GregorianCalendar]) = new N[java.util.GregorianCalendar]
+
+  def aFunc[A](a: NE[A]) = new AA[A]
+  def aFunc[A](a: NZ[A]) = new AA[A]
+
+  def aFunc[A](a: NN[A]) = new BB[A]
+
+  def aFunc[A](a: NQ[A]) = new BB[A]
+
+  def bFunc[T](e1: N[T]) = {}
+
+  def typeMe2 {
+    val x = aFunc(4F)
+    bFunc(x)
+  }
+  def typeMe1 {
+    bFunc(aFunc(4F))
+  }
+}
diff --git a/test/files/pos/t4457_1.scala b/test/files/pos/t4457_1.scala
new file mode 100644
index 0000000000..32edd6cfdc
--- /dev/null
+++ b/test/files/pos/t4457_1.scala
@@ -0,0 +1,26 @@
+object ImplicitConvAmbiguity2 {
+
+  class N[T]
+  class NE[T] extends N[T]
+  class NN[T] extends N[T]
+  class AA[A]
+  class BB[A]
+
+  implicit def conv1(i: Float) = new NE[Float]
+  implicit def conv3(op: AA[java.util.TooManyListenersException]) = new N[java.util.TooManyListenersException]
+  implicit def conv4(op: AA[Float]) = new N[Float]
+  implicit def conv5(e: BB[java.util.GregorianCalendar]) = new N[java.util.GregorianCalendar]
+
+  def aFunc[A](a: NE[A]) = new AA[A]
+  def aFunc[A](a: NN[A]) = new BB[A]
+
+  def bFunc[T](e1: N[T]) = {}
+
+  def typeMe1 {
+    val x = aFunc(4F)
+    bFunc(x)
+  }
+  def typeMe2 {
+    bFunc(aFunc(4F))
+  }
+}