From 170f1ffc91955615fb8005f59df3812711f88354 Mon Sep 17 00:00:00 2001
From: noti0na1 <noti0na1@users.noreply.github.com>
Date: Sun, 26 Oct 2025 13:12:48 +0100
Subject: [PATCH] Cleanup the type of UnApply trees in posttyper

---
 .../src/dotty/tools/dotc/transform/PostTyper.scala |  5 ++++-
 tests/pos-custom-args/captures/i24207.scala        | 14 ++++++++++++++
 tests/pos/i24207.scala                             | 12 ++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 tests/pos-custom-args/captures/i24207.scala
 create mode 100644 tests/pos/i24207.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
index d1824abf9c0f..29baf816da5e 100644
--- a/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PostTyper.scala
@@ -523,7 +523,10 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
         case UnApply(fun, implicits, patterns) =>
           // Reverse transform order for the same reason as in `app1` above.
           val patterns1 = transform(patterns)
-          cpy.UnApply(tree)(transform(fun), transform(implicits), patterns1)
+          val tree1 = cpy.UnApply(tree)(transform(fun), transform(implicits), patterns1)
+          // The pickling of UnApply trees uses the tpe of the tree,
+          // so we need to clean retains from it here
+          tree1.withType(transformAnnotsIn(CleanupRetains()(tree1.tpe)))
         case tree: TypeApply =>
           if tree.symbol == defn.QuotedTypeModule_of then
             ctx.compilationUnit.needsStaging = true
diff --git a/tests/pos-custom-args/captures/i24207.scala b/tests/pos-custom-args/captures/i24207.scala
new file mode 100644
index 000000000000..075b42315a3c
--- /dev/null
+++ b/tests/pos-custom-args/captures/i24207.scala
@@ -0,0 +1,14 @@
+import language.experimental.captureChecking
+
+class Generator:
+  private def generateTable(table: Table) =
+    val (ownRelations, _) = calculateOwnRelations(table)
+    ownRelations
+
+  private def calculateOwnRelations(table: Table) =
+    val ownRelations = table.relations.filter(_.association.isDefined)
+    (ownRelations, Nil)
+
+case class Table(relations: Seq[TableRelation])
+case class TableRelation(association: Option[Association])
+trait Association
diff --git a/tests/pos/i24207.scala b/tests/pos/i24207.scala
new file mode 100644
index 000000000000..557b6f982f2b
--- /dev/null
+++ b/tests/pos/i24207.scala
@@ -0,0 +1,12 @@
+class Generator:
+  private def generateTable(table: Table) =
+    val (ownRelations, _) = calculateOwnRelations(table)
+    ownRelations
+
+  private def calculateOwnRelations(table: Table) =
+    val ownRelations = table.relations.filter(_.association.isDefined)
+    (ownRelations, Nil)
+
+case class Table(relations: Seq[TableRelation])
+case class TableRelation(association: Option[Association])
+trait Association