Fix regression in specialization of traits

Introduced in 2bde392

The previous commit defends the intended part of the change,
which was discussed in scala/scala-dev#36

Author: retronym

src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala

@@ -763,11 +763,11 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers {
           // was: new Forward(specMember) {
           //   override def target = m.owner.info.member(specializedName(m, env))
           // }
-        } else if (!sClass.isTrait && m.isMethod && !m.hasAccessorFlag) { // other concrete methods
+        } else if (!(sClass.isTrait && m.isDeferred) && m.isMethod && !m.hasAccessorFlag) { // other concrete methods
           // log("other concrete " + m)
           forwardToOverload(m)
 
-        } else if (!sClass.isTrait && m.isMethod && m.hasFlag(LAZY)) {
+        } else if (!(sClass.isTrait && m.isDeferred) && m.isMethod && m.hasFlag(LAZY)) {
           forwardToOverload(m)
 
         } else if (m.isValue && !m.isMethod) { // concrete value definition

test/files/run/t10277.check

@@ -0,0 +1,4 @@
+put$mcJ$sp
+fillRange$mcJ$sp
+fillRange$mcJ$sp$
+fillRange$mcJ$sp

test/files/run/t10277.scala

@@ -0,0 +1,28 @@
+trait Column {}
+
+trait TypedColumn[@specialized(Long, Double) T] extends Column {
+  def put(idx: Int, value: T): Unit
+
+  def fillRange(start: Int, len: Int, value: T): Unit = {
+    var idx = start
+    val end = start + len
+    while (idx < end) {
+      put(idx, value)
+      idx += 1
+    }
+  }
+}
+
+final class LongColumn extends TypedColumn[Long] {
+  override def put(idx: Int, value: Long): Unit = {
+    val frames = Thread.currentThread().getStackTrace.toList.drop(1).takeWhile(_.getMethodName != "main")
+    println(frames.map(_.getMethodName).mkString("\n"))
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val c = new LongColumn
+    c.fillRange(0, 1, 10L)
+  }
+}

test/files/run/t10277b.check

@@ -0,0 +1,4 @@
+g$mcI$sp
+g$mcI$sp$
+g$mcI$sp
+f$mcI$sp

test/files/run/t10277b.scala

@@ -0,0 +1,20 @@
+trait A[@specialized(Int) T] {
+  def f(x: T): Unit
+}
+
+trait B[@specialized(Int) T] {
+  def g(x: T): Unit = {
+    val frames = Thread.currentThread().getStackTrace.toList.drop(1).takeWhile(_.getMethodName != "main")
+    println(frames.map(_.getMethodName).mkString("\n"))
+  }
+}
+
+class C[@specialized(Int) T] extends A[T] with B[T] {
+  def f(x: T): Unit = g(x)
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    new C[Int].f(0)
+  }
+}