Strip synthetic ascriptions from inlined calls

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

@@ -831,6 +831,16 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
     }
   }
 
+  /** Strip `Typed` nodes, recursing into `Block` nodes. */
+  def stripSyntheticTyped(tree: Tree)(using Context): Tree =
+    unsplice(tree) match
+      case Typed(expr, _) if tree.span.isSynthetic =>
+        stripSyntheticTyped(expr)
+      case Block(stats, expr) =>
+        cpy.Block(tree)(stats, stripSyntheticTyped(expr))
+      case _ =>
+        tree
+
   /** The type and term arguments of a possibly curried call, in the order they are given */
   def allArgss(tree: Tree): List[List[Tree]] =
     @tailrec

compiler/src/dotty/tools/dotc/inlines/Inliner.scala

@@ -790,7 +790,7 @@ class Inliner(val call: tpd.Tree)(using Context):
       }
 
       // Run a typing pass over the inlined tree. See InlineTyper for details.
-      val expansion1 = inlineTyper.typed(expansion)(using inlineCtx)
+      val expansion1 = inlineTyper.typed(stripSyntheticTyped(expansion))(using inlineCtx)
 
       if (ctx.settings.verbose.value) {
         inlining.println(i"to inline = $rhsToInline")

tests/run/i24420-inline-local-ref.check

@@ -0,0 +1 @@
+1

tests/run/i24420-inline-local-ref.scala

@@ -0,0 +1,12 @@
+inline def f(): Long =
+  1L
+
+inline def g(): Long =
+  inline val x = f()
+  x
+
+inline def h(): Long =
+  inline if g() > 0L then 1L else 0L
+
+@main def Test: Unit =
+  println(h())

tests/run/i24420-transparent-inline-local-ref.check

@@ -0,0 +1 @@
+1

tests/run/i24420-transparent-inline-local-ref.scala

@@ -0,0 +1,12 @@
+transparent inline def f(): Long =
+  1L
+
+transparent inline def g(): Long =
+  inline val x = f()
+  x
+
+transparent inline def h(): Long =
+  inline if g() > 0L then 1L else 0L
+
+@main def Test: Unit =
+  println(h())