From 0c01501e1dfcbaf87675fa5192f25c4412a4815b Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Thu, 16 Nov 2017 15:02:03 +0100
Subject: [PATCH] Fix #3480: Fix expanded name

Expanded name behaved different from what would be expected
by the fullNameSeparated conventions. This led to local
dummies creeping in the expanded names for local definitions
in templates.
---
 .../src/dotty/tools/dotc/core/NameOps.scala   | 11 +++++-----
 .../tools/dotc/core/SymDenotations.scala      | 20 +++++++++++--------
 tests/pos/i3480.scala                         |  5 +++++
 tests/run/i3006b.check                        |  6 +++---
 4 files changed, 26 insertions(+), 16 deletions(-)
 create mode 100644 tests/pos/i3480.scala

diff --git a/compiler/src/dotty/tools/dotc/core/NameOps.scala b/compiler/src/dotty/tools/dotc/core/NameOps.scala
index 4e568861e401..b1c618a15a50 100644
--- a/compiler/src/dotty/tools/dotc/core/NameOps.scala
+++ b/compiler/src/dotty/tools/dotc/core/NameOps.scala
@@ -114,11 +114,12 @@ object NameOps {
       else name.toTermName.exclude(AvoidClashName)
     }
 
-    def expandedName(base: Symbol, kind: QualifiedNameKind = ExpandedName)(implicit ctx: Context): N = {
-      val prefix =
-        if (base.name.is(ExpandedName)) base.name else base.fullNameSeparated(ExpandPrefixName)
-      likeSpaced { kind(prefix.toTermName, name.toTermName) }
-    }
+    /** The expanded name.
+     *  This is the fully qualified name of `base` with `ExpandPrefixName` as separator,
+     *  followed by `kind` and the name.
+     */
+    def expandedName(base: Symbol, kind: QualifiedNameKind = ExpandedName)(implicit ctx: Context): N =
+      likeSpaced { base.fullNameSeparated(ExpandPrefixName, kind, name) }
 
     /** Revert the expanded name. */
     def unexpandedName: N = likeSpaced {
diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index 145913261053..1703a0c834ff 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -391,18 +391,23 @@ object SymDenotations {
      *  Drops package objects. Represents each term in the owner chain by a simple `_$`.
      */
     def fullNameSeparated(kind: QualifiedNameKind)(implicit ctx: Context): Name =
-      if (symbol == NoSymbol ||
-          owner == NoSymbol ||
-          owner.isEffectiveRoot ||
-          kind == FlatName && owner.is(PackageClass)) name
+      maybeOwner.fullNameSeparated(kind, kind, name)
+
+    /** The encoded full path name of this denotation (separated by `prefixKind`),
+     *  followed by the separator implied by `kind` and the given `name`.
+     *  Drops package objects. Represents each term in the owner chain by a simple `_$`.
+     */
+     def fullNameSeparated(prefixKind: QualifiedNameKind, kind: QualifiedNameKind, name: Name)(implicit ctx: Context): Name =
+      if (symbol == NoSymbol || isEffectiveRoot || kind == FlatName && is(PackageClass))
+        name
       else {
         var filler = ""
-        var encl = owner
+        var encl = symbol
         while (!encl.isClass && !encl.isPackageObject) {
           encl = encl.owner
           filler += "_$"
         }
-        var prefix = encl.fullNameSeparated(kind)
+        var prefix = encl.fullNameSeparated(prefixKind)
         if (kind.separator == "$")
           // duplicate scalac's behavior: don't write a double '$$' for module class members.
           prefix = prefix.exclude(ModuleClassName)
@@ -412,10 +417,9 @@ object SymDenotations {
           case name: SimpleName => qualify(name)
           case name @ AnyQualifiedName(_, _) => qualify(name.mangled.toSimpleName)
         }
-        if (isType) fn.toTypeName else fn.toTermName
+        if (name.isType) fn.toTypeName else fn.toTermName
       }
 
-
     /** The encoded flat name of this denotation, where joined names are separated by `separator` characters. */
     def flatName(implicit ctx: Context): Name = fullNameSeparated(FlatName)
 
diff --git a/tests/pos/i3480.scala b/tests/pos/i3480.scala
new file mode 100644
index 000000000000..05aa5ecf3f07
--- /dev/null
+++ b/tests/pos/i3480.scala
@@ -0,0 +1,5 @@
+class Test {
+  def foo(x: PartialFunction[Int, Int]) = x(0)
+
+  foo({ case i => i})
+}
diff --git a/tests/run/i3006b.check b/tests/run/i3006b.check
index 78405f03836c..b62605500d51 100644
--- a/tests/run/i3006b.check
+++ b/tests/run/i3006b.check
@@ -1,3 +1,3 @@
-Foo$$init$$$bar$1
-Foo$$init$$$bar$2
-Bar$$init$$$bar$1
+Foo$$_$bar$1
+Foo$$_$bar$2
+Bar$$_$bar$1