From fe6574ce384449aa21add25f387e3a71cffe726b Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Mon, 7 Feb 2022 11:04:25 +0000
Subject: [PATCH] Fix invariant quote type holes

---
 .../src/scala/quoted/runtime/impl/QuotesImpl.scala  |  5 +++--
 tests/pos-macros/i12343/Macro.scala                 | 13 +++++++++++++
 tests/pos-macros/i12343/Test.scala                  |  7 +++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 tests/pos-macros/i12343/Macro.scala
 create mode 100644 tests/pos-macros/i12343/Test.scala

diff --git a/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala b/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
index ae3067a894d7..000f84199c27 100644
--- a/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
+++ b/compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala
@@ -3056,8 +3056,9 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
       // that we have found, seal them in a quoted.Type and add them to the result
       def typeHoleApproximation(sym: Symbol) =
         val fromAboveAnnot = sym.hasAnnotation(dotc.core.Symbols.defn.QuotedRuntimePatterns_fromAboveAnnot)
-        val approx = ctx1.gadt.approximation(sym, !fromAboveAnnot)
-        reflect.TypeReprMethods.asType(approx)
+        val fullBounds = ctx1.gadt.fullBounds(sym)
+        val tp = if fromAboveAnnot then fullBounds.hi else fullBounds.lo
+        reflect.TypeReprMethods.asType(tp)
       matchings.map { tup =>
         Tuple.fromIArray(typeHoles.map(typeHoleApproximation).toArray.asInstanceOf[IArray[Object]]) ++ tup
       }
diff --git a/tests/pos-macros/i12343/Macro.scala b/tests/pos-macros/i12343/Macro.scala
new file mode 100644
index 000000000000..03642dd1f4af
--- /dev/null
+++ b/tests/pos-macros/i12343/Macro.scala
@@ -0,0 +1,13 @@
+package test
+
+import scala.quoted.*
+
+object Macro:
+  def covImpl(arg: Expr[Any])(using Quotes): Expr[Any] = arg match // Covariant (List)
+    case '{ $h : List[h] } => '{ $h : List[h] }
+
+  def invImpl(arg: Expr[Any])(using Quotes): Expr[Any] = arg match // Invariant (Set)
+    case '{ $h : Set[h] } => '{ $h : Set[h] }
+
+  transparent inline def cov(inline arg: Any): Any = ${ covImpl('arg) }
+  transparent inline def inv(inline arg: Any): Any = ${ invImpl('arg) }
diff --git a/tests/pos-macros/i12343/Test.scala b/tests/pos-macros/i12343/Test.scala
new file mode 100644
index 000000000000..ef23a9c16725
--- /dev/null
+++ b/tests/pos-macros/i12343/Test.scala
@@ -0,0 +1,7 @@
+package test
+
+object Test:
+  val cov1: List[Boolean]          = Macro.cov(List(true))
+  val inv1: Set[Boolean]           = Macro.inv(Set(true))
+  def cov2[X](a: List[X]): List[X] = Macro.cov(a)
+  def inv2[X](a: Set[X]): Set[X]   = Macro.inv(a) // doesn't compile; Set[Nothing] is inferred