Merge pull request #455 from scala/backport-lts-3.3-23331

Backport "Revert "Make overload pruning based on result types less aggressive (scala#21744)" in main" to 3.3 LTS

Author: tgodzik

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -1942,27 +1942,16 @@ 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
@@ -2308,7 +2297,6 @@ 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)) =>

tests/pos/i21410.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 = ???
+  }
+}