Merge pull request #10913 from dotty-staging/fix-#10495

Take expected and excluded flags into account when checking for ambig…

Author: odersky

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

@@ -334,8 +334,11 @@ class Typer extends Namer
               checkNoOuterDefs(denot, outer, prevCtx)
             else if !owner.is(Package) then
               val scope = if owner.isClass then owner.info.decls else outer.scope
-              if scope.lookup(name).exists then
-                val symsMatch = scope.lookupAll(name).exists(denot.containsSym)
+              val competing = scope.denotsNamed(name).filterWithFlags(required, excluded)
+              if competing.exists then
+                val symsMatch = competing
+                  .filterWithPredicate(sd => denot.containsSym(sd.symbol))
+                  .exists
                 if !symsMatch && !suppressErrors then
                   report.errorOrMigrationWarning(
                     AmbiguousReference(name, Definition, Inheritance, prevCtx)(using outer),

tests/pos/i10495.scala

@@ -0,0 +1,7 @@
+class Foo:
+  extension(x: String) def run: Unit  = ???
+
+object Bar extends Foo:
+  def run(v: Int): Unit = ???
+
+  "ABC".run  // Failed before:  Reference to run is ambiguous...