Fix #20512: Try implicit searching after finding dynamic select (#22318)

Fix #20512

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

@@ -852,11 +852,11 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
       else EmptyTree
 
     def dynamicSelect(pt: Type) =
-        val tree2 = cpy.Select(tree0)(untpd.TypedSplice(qual), selName)
-        if pt.isInstanceOf[FunOrPolyProto] || pt == LhsProto then
-          assignType(tree2, TryDynamicCallType)
-        else
-          typedDynamicSelect(tree2, Nil, pt)
+      val tree2 = cpy.Select(tree0)(untpd.TypedSplice(qual), selName)
+      if pt.isInstanceOf[FunOrPolyProto] || pt == LhsProto then
+        assignType(tree2, TryDynamicCallType)
+      else
+        typedDynamicSelect(tree2, Nil, pt)
 
     // Otherwise, if the qualifier derives from class Dynamic, expand to a
     // dynamic dispatch using selectDynamic or applyDynamic
@@ -885,7 +885,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
                 // Reject corner case where selectDynamic needs annother selectDynamic to be called. E.g. as in neg/unselectable-fields.scala.
                 report.error(i"Cannot use selectDynamic here since it needs another selectDynamic to be invoked", tree.srcPos)
               case _ =>
-            dynSelected.ensureConforms(fieldType)
+            adapt(dynSelected, defn.AnyType).ensureConforms(fieldType)
           case _ => EmptyTree
       else EmptyTree
 

compiler/test/dotc/pos-test-pickling.blacklist

@@ -70,6 +70,7 @@ i18211.scala
 10867.scala
 named-tuples1.scala
 i20897.scala
+i20512.scala
 
 # Opaque type
 i5720.scala

tests/pos/i20512.scala

@@ -0,0 +1,26 @@
+import language.experimental.namedTuples
+
+import NamedTuple.*
+
+trait Selector1 extends Selectable {
+  type Fields = (int: Int, str: String)
+
+  def selectDynamic(name: String)(using name.type <:< Tuple.Union[NamedTuple.Names[Fields]]) = ???
+}
+
+def test20512 = {
+  val s: Selector1 = new Selector1 {}
+  val int = s.int
+  val str = s.str
+}
+
+trait Ctx
+
+class Selector2 extends Selectable:
+  type Fields = (bar: Int, baz: Int)
+  def selectDynamic(fieldName: String)(using Ctx): Any = ???
+
+def test22023(using Ctx) =
+  val f = Selector2()
+  val bar = f.bar
+  val baz = f.baz