SI-6278 fixed: synthetic implicit def must sort with its associated implicit class

Add a case to the ad-hoc (or add-hack) addSynthetics to keep the trees close.

This relies on naming convention, so changes in naming of the implicit def
would require an update here.

2 files changed, 36 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 21d61ff7b1..d055c6ec48 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2743,12 +2743,18 @@ trait Typers extends Modes with Adaptations with Tags {
           // this code by associating defaults and companion objects
           // with the original tree instead of the new symbol.
           def matches(stat: Tree, synt: Tree) = (stat, synt) match {
+            // synt is default arg for stat
             case (DefDef(_, statName, _, _, _, _), DefDef(mods, syntName, _, _, _, _)) =>
               mods.hasDefaultFlag && syntName.toString.startsWith(statName.toString)
 
+            // synt is companion module
             case (ClassDef(_, className, _, _), ModuleDef(_, moduleName, _)) =>
               className.toTermName == moduleName
 
+            // synt is implicit def for implicit class (#6278)
+            case (ClassDef(cmods, cname, _, _), DefDef(dmods, dname, _, _, _, _)) =>
+              cmods.isImplicit && dmods.isImplicit && cname.toTermName == dname
+
             case _ => false
           }
 
diff --git a/test/files/pos/t6278-synth-def.scala b/test/files/pos/t6278-synth-def.scala
new file mode 100644
index 0000000000..b8b660fbe3
--- /dev/null
+++ b/test/files/pos/t6278-synth-def.scala
@@ -0,0 +1,30 @@
+
+package t6278
+
+import language.implicitConversions
+
+object test {
+  def ok() {
+    class Foo(val i: Int) {
+      def foo[A](body: =>A): A = body
+    }
+    implicit def toFoo(i: Int): Foo = new Foo(i)
+
+    val k = 1
+    k foo println("k?")
+    val j = 2
+  }
+  def nope() {
+    implicit class Foo(val i: Int) {
+      def foo[A](body: =>A): A = body
+    }
+
+    val k = 1
+    k foo println("k?")
+    //lazy
+    val j = 2
+  }
+  def main(args: Array[String]) {
+    ok(); nope()
+  }
+}