Don't module class for unhabitated fields (#23634)

Alex1005a · WojciechMazur · commit 482959bacf03 · 2025-08-01T13:41:05.000+02:00
Fix #23576 [Cherry-picked 17625b5]
diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -685,7 +685,7 @@ object SpaceEngine {
           val refined = trace(i"refineUsingParent($tp, $sym1, $mixins)")(TypeOps.refineUsingParent(tp, sym1, mixins))
 
           def containsUninhabitedField(tp: Type): Boolean =
-            tp.fields.exists { field =>
+            !tp.typeSymbol.is(ModuleClass) && tp.fields.exists { field =>
               !field.symbol.flags.is(Lazy) && field.info.dealias.isBottomType
             }
 

Original file line number	Diff line number	Diff line change
`@@ -685,7 +685,7 @@ object SpaceEngine {`
`685`	`685`	`val refined = trace(i"refineUsingParent($tp, $sym1, $mixins)")(TypeOps.refineUsingParent(tp, sym1, mixins))`
`686`	`686`
`687`	`687`	`def containsUninhabitedField(tp: Type): Boolean =`
`688`		`- tp.fields.exists { field =>`
	`688`	`+ !tp.typeSymbol.is(ModuleClass) && tp.fields.exists { field =>`
`689`	`689`	`!field.symbol.flags.is(Lazy) && field.info.dealias.isBottomType`
`690`	`690`	`}`
`691`	`691`