From 4c91a0bf9d54fe4490f9992354b98605a3bec6c4 Mon Sep 17 00:00:00 2001
From: Dale Wijnand <dale.wijnand@gmail.com>
Date: Fri, 14 Feb 2025 10:01:21 +0000
Subject: [PATCH] Avoid crash in uninhab check in Space

[Cherry-picked 899d4078a0d83ccdd8663a4ff11f79b1350e8a8e]
---
 .../src/dotty/tools/dotc/transform/patmat/Space.scala    | 2 +-
 tests/pos/i22518.scala                                   | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 tests/pos/i22518.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
index 9cf94877328b..8f015bcd5f42 100644
--- a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
+++ b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -655,7 +655,7 @@ object SpaceEngine {
           val superType = child.typeRef.superType
           if typeArgs.exists(_.isBottomType) && superType.isInstanceOf[ClassInfo] then
             val parentClass = superType.asInstanceOf[ClassInfo].declaredParents.find(_.classSymbol == parent).get
-            val paramTypeMap = Map.from(parentClass.argTypes.map(_.typeSymbol).zip(typeArgs))
+            val paramTypeMap = Map.from(parentClass.argInfos.map(_.typeSymbol).zip(typeArgs))
             val substArgs = child.typeRef.typeParamSymbols.map(param => paramTypeMap.getOrElse(param, WildcardType))
             substArgs
           else Nil
diff --git a/tests/pos/i22518.scala b/tests/pos/i22518.scala
new file mode 100644
index 000000000000..d530159701c4
--- /dev/null
+++ b/tests/pos/i22518.scala
@@ -0,0 +1,9 @@
+sealed trait Foo[T]
+class Bar extends Foo[?]
+
+def mkFoo[T]: Foo[T] =
+  ???
+
+def test: Unit =
+  mkFoo match
+    case _ => ()