Merge pull request #599 from som-snytt/ticket/5779-numeq-warn

SI-5779: Wrong warning message (comparing Number)

3 files changed, 25 insertions, 3 deletions

diff --git a/src/compiler/scala/reflect/internal/Definitions.scala b/src/compiler/scala/reflect/internal/Definitions.scala
index 0612dcdfd4..00afdd37a6 100644
--- a/src/compiler/scala/reflect/internal/Definitions.scala
+++ b/src/compiler/scala/reflect/internal/Definitions.scala
@@ -404,6 +404,7 @@ trait Definitions extends reflect.api.StandardDefinitions {
     lazy val JavaSerializableClass = requiredClass[java.io.Serializable] modifyInfo fixupAsAnyTrait
     lazy val ComparableClass       = requiredClass[java.lang.Comparable[_]] modifyInfo fixupAsAnyTrait
     lazy val JavaCloneableClass    = requiredClass[java.lang.Cloneable]
+    lazy val JavaNumberClass       = requiredClass[java.lang.Number]
     lazy val RemoteInterfaceClass  = requiredClass[java.rmi.Remote]
     lazy val RemoteExceptionClass  = requiredClass[java.rmi.RemoteException]
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 4e578e3f0d..3373878beb 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1084,8 +1084,16 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R
         def isEitherNullable     = (NullClass.tpe <:< receiver.info) || (NullClass.tpe <:< actual.info)
         def isBoolean(s: Symbol) = unboxedValueClass(s) == BooleanClass
         def isUnit(s: Symbol)    = unboxedValueClass(s) == UnitClass
-        def isNumeric(s: Symbol) = isNumericValueClass(unboxedValueClass(s)) || (s isSubClass ScalaNumberClass)
-        def isSpecial(s: Symbol) = isPrimitiveValueClass(unboxedValueClass(s)) || (s isSubClass ScalaNumberClass) || isMaybeValue(s)
+        def isNumeric(s: Symbol) = isNumericValueClass(unboxedValueClass(s)) || isAnyNumber(s)
+        def isScalaNumber(s: Symbol) = s isSubClass ScalaNumberClass
+        // test is behind a platform guard
+        def isJavaNumber(s: Symbol) = !forMSIL && (s isSubClass JavaNumberClass)
+        // includes java.lang.Number if appropriate [SI-5779]
+        def isAnyNumber(s: Symbol) = isScalaNumber(s) || isJavaNumber(s)
+        def isMaybeAnyValue(s: Symbol) = isPrimitiveValueClass(unboxedValueClass(s)) || isMaybeValue(s)
+        // used to short-circuit unrelatedTypes check if both sides are special
+        def isSpecial(s: Symbol) = isMaybeAnyValue(s) || isAnyNumber(s)
+        // unused
         def possibleNumericCount = onSyms(_ filter (x => isNumeric(x) || isMaybeValue(x)) size)
         val nullCount            = onSyms(_ filter (_ == NullClass) size)
 
@@ -1155,7 +1163,7 @@ abstract class RefChecks extends InfoTransform with reflect.internal.transform.R
           if (isCaseEquals) {
             def thisCase = receiver.info.member(nme.equals_).owner
             actual.info.baseClasses.find(_.isCase) match {
-              case Some(p) if (p != thisCase) => nonSensible("case class ", false)
+              case Some(p) if p != thisCase => nonSensible("case class ", false)
               case None =>
                 // stronger message on (Some(1) == None)
                 //if (receiver.isCase && receiver.isEffectivelyFinal && !(receiver isSubClass actual)) nonSensiblyNeq()
diff --git a/test/files/pos/t5779-numeq-warn.scala b/test/files/pos/t5779-numeq-warn.scala
new file mode 100644
index 0000000000..76ef2970fd
--- /dev/null
+++ b/test/files/pos/t5779-numeq-warn.scala
@@ -0,0 +1,13 @@
+
+object Test {
+  def main(args: Array[String]) {
+    val d: Double = (BigInt(1) << 64).toDouble
+    val f: Float = d.toFloat
+    val n: java.lang.Number = d.toFloat
+    assert (d == f)   // ok
+    assert (d == n)   // was: comparing values of types Double and Number using `==' will always yield false
+    assert (n == d)   // was: Number and Double are unrelated: they will most likely never compare equal
+    assert (f == n)
+    assert (n == f)
+  }
+}