From 22fd5454e9cdefb75f6430f86d0d3b38adb9086c Mon Sep 17 00:00:00 2001
From: Carlos Quiroz <carlos.m.quiroz@gmail.com>
Date: Sun, 6 Oct 2019 14:59:40 -0300
Subject: [PATCH] Trait constructors on scala.js

Signed-off-by: Carlos Quiroz <carlos.m.quiroz@gmail.com>
---
 .../tools/dotc/transform/LinkScala2Impls.scala      | 13 ++++++++++++-
 project/Build.scala                                 |  1 +
 sandbox/scalajs/src/Integral.scala                  | 13 +++++++++++++
 3 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 sandbox/scalajs/src/Integral.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/LinkScala2Impls.scala b/compiler/src/dotty/tools/dotc/transform/LinkScala2Impls.scala
index d97d51142012..1af0082395be 100644
--- a/compiler/src/dotty/tools/dotc/transform/LinkScala2Impls.scala
+++ b/compiler/src/dotty/tools/dotc/transform/LinkScala2Impls.scala
@@ -78,6 +78,12 @@ class LinkScala2Impls extends MiniPhase with IdentityDenotTransformer { thisPhas
         val impl = implMethod(sel.symbol)
         if (impl.exists) Apply(ref(impl), This(currentClass) :: args).withSpan(app.span)
         else app // could have been an abstract method in a trait linked to from a super constructor
+      case Apply(sel @ Select(Super(a, b), _), args)
+      if sel.symbol.owner.is(Scala2x) && currentClass.mixins.contains(sel.symbol.owner) && sel.symbol.isConstructor =>
+        val impl = implMethod(sel.symbol)
+        if (impl.exists)
+        Apply(ref(impl), This(currentClass) :: args).withSpan(app.span)
+        else app // could have been an abstract method in a trait linked to from a super constructor
       case _ =>
         app
     }
@@ -88,8 +94,13 @@ class LinkScala2Impls extends MiniPhase with IdentityDenotTransformer { thisPhas
     val implName = ImplMethName(meth.name.asTermName)
     val cls = meth.owner
     if (cls.isAllOf(Scala2xTrait))
-      if (meth.isConstructor)
+      if (meth.isConstructor) {
+        if (ctx.settings.scalajs.value) {
+        // Is this the static call?
         cls.info.decl(nme.TRAIT_CONSTRUCTOR).symbol
+      } else
+        cls.info.decl(nme.TRAIT_CONSTRUCTOR).symbol
+      }
       else
         cls.info.decl(implName)
           .suchThat(c => FullParameterization.memberSignature(c.info) == meth.signature)
diff --git a/project/Build.scala b/project/Build.scala
index b7a25a63e1e5..533634283d38 100644
--- a/project/Build.scala
+++ b/project/Build.scala
@@ -1001,6 +1001,7 @@ object Build {
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/junit" ** (("*.scala": FileFilter) -- "JUnitAnnotationsParamTest.scala")).get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/niobuffer" ** (("*.scala": FileFilter)  -- "ByteBufferTest.scala")).get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/niocharset" ** (("*.scala": FileFilter)  -- "BaseCharsetTest.scala" -- "Latin1Test.scala" -- "USASCIITest.scala" -- "UTF16Test.scala" -- "UTF8Test.scala")).get
+          ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/scalalib/RangesTest.scala").get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/scalalib" ** (("*.scala": FileFilter)  -- "ArrayBuilderTest.scala" -- "ClassTagTest.scala" -- "EnumerationTest.scala" -- "RangesTest.scala" -- "SymbolTest.scala")).get
           ++ (dir / "shared/src/test/require-sam" ** (("*.scala": FileFilter) -- "SAMTest.scala")).get
         )
diff --git a/sandbox/scalajs/src/Integral.scala b/sandbox/scalajs/src/Integral.scala
new file mode 100644
index 000000000000..fd1478b03748
--- /dev/null
+++ b/sandbox/scalajs/src/Integral.scala
@@ -0,0 +1,13 @@
+package hello
+
+// Minimal reproduction
+object Integral {
+  def main(args: Array[String]): Unit = {
+    trait A[T] extends Ordering[T]
+    case class B[T](v: T) extends A[T] {
+      def compare(x: T, y: T): Int = 0
+    }
+
+    B(0)
+  }
+}