Merge remote-tracking branch 'origin/2.10.x' into pr/merge-210

* commit 'd392d56d6bf8b0ae9072b354e4ec68becd0df679':
  SI-4602 Disable unreliable test of fsc path absolutization
  Update a checkfile from a recent fix.
  SI-7018 Fix memory leak in Attachments.
  SI-4733 - fsc no longer creates a single temp directory for all users.
  Bumped partest MaxPermSize to 128m.
  SI-6891 Fix value class + tailrec crasher.
  Ill-scoped reference checking in TreeCheckers
  Make value classes TreeCheckers friendly
  SI-4602 Make fsc absolutize source file names
  SI-6863 Fix verify error in captured var inited from expr with try/catch
  SI-6932 Remove Batchable trait plus minor clean-ups
  Fix SI-6932 by enabling linearization of callback execution for the internal execution context of Future
  SI-6443 Expand test coverage with varargs, by-name.
  SI-6443 Widen dependent param types in uncurry

Conflicts:
	src/reflect/scala/reflect/internal/Trees.scala
	test/partest

3 files changed, 34 insertions, 6 deletions

diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 0969d9e3fa..745a665062 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -1690,6 +1690,8 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
 
     @inline final def map(f: Symbol => Symbol): Symbol = if (this eq NoSymbol) this else f(this)
 
+    final def toOption: Option[Symbol] = if (exists) Some(this) else None
+
 // ------ cloneing -------------------------------------------------------------------
 
     /** A clone of this symbol. */
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala
index 3c2249bfb5..9b185c1c2d 100644
--- a/src/reflect/scala/reflect/internal/Trees.scala
+++ b/src/reflect/scala/reflect/internal/Trees.scala
@@ -1469,6 +1469,22 @@ trait Trees extends api.Trees { self: SymbolTable =>
       if (tree.hasSymbolField) {
         subst(from, to)
         tree match {
+          case _: DefTree =>
+            val newInfo = symSubst(tree.symbol.info)
+            if (!(newInfo =:= tree.symbol.info)) {
+              debuglog(sm"""
+                |TreeSymSubstituter: updated info of symbol ${tree.symbol}
+                |  Old: ${showRaw(tree.symbol.info, printTypes = true, printIds = true)}
+                |  New: ${showRaw(newInfo, printTypes = true, printIds = true)}""")
+              tree.symbol updateInfo newInfo
+            }
+          case _          =>
+            // no special handling is required for Function or Import nodes here.
+            // as they don't have interesting infos attached to their symbols.
+            // Subsitution of the referenced symbol of Return nodes is handled
+            // in .ChangeOwnerTraverser
+        }
+        tree match {
           case Ident(name0) if tree.symbol != NoSymbol =>
             treeCopy.Ident(tree, tree.symbol.name)
           case Select(qual, name0) if tree.symbol != NoSymbol =>
@@ -1526,6 +1542,14 @@ trait Trees extends api.Trees { self: SymbolTable =>
       t1
     }
   }
+  trait TreeStackTraverser extends Traverser {
+    import collection.mutable
+    val path: mutable.Stack[Tree] = mutable.Stack()
+    abstract override def traverse(t: Tree) = {
+      path push t
+      try super.traverse(t) finally path.pop()
+    }
+  }
 
   def duplicateAndKeepPositions(tree: Tree) = new Duplicator(focusPositions = false) transform tree
 
diff --git a/src/reflect/scala/reflect/macros/Attachments.scala b/src/reflect/scala/reflect/macros/Attachments.scala
index a77cebf415..eeb87fafcc 100644
--- a/src/reflect/scala/reflect/macros/Attachments.scala
+++ b/src/reflect/scala/reflect/macros/Attachments.scala
@@ -44,17 +44,19 @@ abstract class Attachments { self =>
    *  Replaces an existing payload of the same type, if exists.
    */
   def update[T: ClassTag](attachment: T): Attachments { type Pos = self.Pos } =
-    new NonemptyAttachments(this.pos, remove[T].all + attachment)
+    new NonemptyAttachments[Pos](this.pos, remove[T].all + attachment)
 
   /** Creates a copy of this attachment with the payload of the given class type `T` removed. */
   def remove[T: ClassTag]: Attachments { type Pos = self.Pos } = {
     val newAll = all filterNot matchesTag[T]
     if (newAll.isEmpty) pos.asInstanceOf[Attachments { type Pos = self.Pos }]
-    else new NonemptyAttachments(this.pos, newAll)
+    else new NonemptyAttachments[Pos](this.pos, newAll)
   }
+}
 
-  private class NonemptyAttachments(override val pos: Pos, override val all: Set[Any]) extends Attachments {
-    type Pos = self.Pos
-    def withPos(newPos: Pos) = new NonemptyAttachments(newPos, all)
-  }
+// SI-7018: This used to be an inner class of `Attachments`, but that led to a memory leak in the
+// IDE via $outer pointers.
+private final class NonemptyAttachments[P >: Null](override val pos: P, override val all: Set[Any]) extends Attachments {
+  type Pos = P
+  def withPos(newPos: Pos) = new NonemptyAttachments(newPos, all)
 }