Fix #6325: Propagate error type to internal splice

Author: nicolasstucki

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -1181,7 +1181,9 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   /** An extractor for typed splices */
   object Splice {
     def apply(tree: Tree)(implicit ctx: Context): Tree = {
-      val argType = tree.tpe.baseType(defn.QuotedExprClass).argTypesHi.head
+      val argType =
+        if (tree.tpe.widen.isError) tree.tpe.widen
+        else tree.tpe.baseType(defn.QuotedExprClass).argTypesHi.head
       ref(defn.InternalQuoted_exprSplice).appliedToType(argType).appliedTo(tree)
     }
     def unapply(tree: Tree)(implicit ctx: Context): Option[Tree] = tree match {

tests/neg/i6325.scala

@@ -0,0 +1,7 @@
+//import scala.quoted.matching.Bind
+object Test {
+  def res(x: quoted.Expr[Int]) given tasty.Reflection: quoted.Expr[Int] = x match {
+    case '{ 1 + (${Bind(b)}: Int) } => ??? // error: Not found: Bind
+    case _ => ???
+  }
+}