From 5298be08fc3dbc9aa509d48a8c75bb3cd03deadc Mon Sep 17 00:00:00 2001
From: Wojciech Mazur <wmazur@virtuslab.com>
Date: Mon, 9 Jun 2025 11:37:55 +0200
Subject: [PATCH 1/2] Add regression test for type inference #22713

---
 tests/pos/i22713.scala | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 tests/pos/i22713.scala

diff --git a/tests/pos/i22713.scala b/tests/pos/i22713.scala
new file mode 100644
index 000000000000..ec3e12cebaec
--- /dev/null
+++ b/tests/pos/i22713.scala
@@ -0,0 +1,13 @@
+import java.util.concurrent.ScheduledExecutorService
+import java.util.concurrent.TimeUnit
+
+def Test = {
+  val worker: ScheduledExecutorService = ???
+  object Worker extends Runnable {
+    def fails(): Either[Exception, Unit] = Right(worker.schedule(this, 5, TimeUnit.NANOSECONDS))
+    def works(): Either[Exception, Unit] = Right {
+      worker.schedule(this, 5, TimeUnit.NANOSECONDS); ()
+    }
+    def run(): Unit = ???
+  }
+}

From 17f3bdead8ad1df1eef4a742191f4d61002058c0 Mon Sep 17 00:00:00 2001
From: Wojciech Mazur <wmazur@virtuslab.com>
Date: Tue, 8 Apr 2025 15:03:08 +0200
Subject: [PATCH 2/2] Revert "Make overload pruning based on result types less
 aggressive (#21744)"

This reverts commit 93af7b8c7dde6b5a4c2993e00820733fb34fd52d, reversing
changes made to 7d79c561d2f7cc0b831a072c0cd4f722a8246062.
---
 .../dotty/tools/dotc/typer/Applications.scala    | 16 ++--------------
 tests/pos/i21410.scala                           | 12 ------------
 tests/pos/i21410b.scala                          | 10 ----------
 tests/pos/i21410c.scala                          | 11 -----------
 4 files changed, 2 insertions(+), 47 deletions(-)
 delete mode 100644 tests/pos/i21410.scala
 delete mode 100644 tests/pos/i21410b.scala
 delete mode 100644 tests/pos/i21410c.scala

diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala
index 78e2099511d7..99bfeef6b46c 100644
--- a/compiler/src/dotty/tools/dotc/typer/Applications.scala
+++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala
@@ -2169,27 +2169,16 @@ trait Applications extends Compatibility {
   def resolveOverloaded(alts: List[TermRef], pt: Type)(using Context): List[TermRef] =
     record("resolveOverloaded")
 
-    /** Is `alt` a method or polytype whose approximated result type after the first value parameter
+    /** Is `alt` a method or polytype whose result type after the first value parameter
      *  section conforms to the expected type `resultType`? If `resultType`
      *  is a `IgnoredProto`, pick the underlying type instead.
-     *
-     *  Using an approximated result type is necessary to avoid false negatives
-     *  due to incomplete type inference such as in tests/pos/i21410.scala and tests/pos/i21410b.scala.
      */
     def resultConforms(altSym: Symbol, altType: Type, resultType: Type)(using Context): Boolean =
       resultType.revealIgnored match {
         case resultType: ValueType =>
           altType.widen match {
             case tp: PolyType => resultConforms(altSym, instantiateWithTypeVars(tp), resultType)
-            case tp: MethodType =>
-              val wildRes = wildApprox(tp.resultType)
-
-              class ResultApprox extends AvoidWildcardsMap:
-                // Avoid false negatives by approximating to a lower bound
-                variance = -1
-
-              val approx = ResultApprox()(wildRes)
-              constrainResult(altSym, approx, resultType)
+            case tp: MethodType => constrainResult(altSym, tp.resultType, resultType)
             case _ => true
           }
         case _ => true
@@ -2561,7 +2550,6 @@ trait Applications extends Compatibility {
       if t.exists && alt.symbol.exists then
         val (trimmed, skipped) = trimParamss(t.stripPoly, alt.symbol.rawParamss)
         val mappedSym = alt.symbol.asTerm.copy(info = t)
-        mappedSym.annotations = alt.symbol.annotations
         mappedSym.rawParamss = trimmed
         val (pre, totalSkipped) = mappedAltInfo(alt.symbol) match
           case Some((pre, prevSkipped)) =>
diff --git a/tests/pos/i21410.scala b/tests/pos/i21410.scala
deleted file mode 100644
index c3ba3ea862bc..000000000000
--- a/tests/pos/i21410.scala
+++ /dev/null
@@ -1,12 +0,0 @@
-class A
-object Test:
-  type F[X] <: Any = X match
-    case A => Int
-
-  def foo[T](x: String): T = ???
-  def foo[U](x: U): F[U] = ???
-
-  val x1 = foo(A())
-  val y: Int = x1
-
-  val x2: Int = foo(A()) // error
diff --git a/tests/pos/i21410b.scala b/tests/pos/i21410b.scala
deleted file mode 100644
index a17ad59bc59e..000000000000
--- a/tests/pos/i21410b.scala
+++ /dev/null
@@ -1,10 +0,0 @@
-object Test:
-  def foo[T](x: Option[T]): T = ???
-  def foo[T <: Tuple](x: T): Tuple.Map[T, List] = ???
-
-  val tup: (Int, String) = (1, "")
-
-  val x = foo(tup)
-  val y: (List[Int], List[String]) = x
-
-  val x2: (List[Int], List[String]) = foo(tup) // error
diff --git a/tests/pos/i21410c.scala b/tests/pos/i21410c.scala
deleted file mode 100644
index 21f69fec20fa..000000000000
--- a/tests/pos/i21410c.scala
+++ /dev/null
@@ -1,11 +0,0 @@
-class AppliedPIso[A, B]()
-case class User(age: Int)
-
-object Test:
-  extension [From, To](from: From)
-    def focus(): AppliedPIso[From, From] = ???
-    transparent inline def focus(inline lambda: (From => To)): Any = ???
-
-
-  val u = User(1)
-  val ap: AppliedPIso[User, User] = u.focus(_.age) // error