Fix scala#15405: Dealias Or type constituents when finding its dominator

anatoliykmetyuk · anatoliykmetyuk · commit b9eeece8ed0d · 2022-06-10T16:20:37.000+02:00
diff --git a/compiler/src/dotty/tools/dotc/core/TypeOps.scala b/compiler/src/dotty/tools/dotc/core/TypeOps.scala
@@ -345,7 +345,7 @@ object TypeOps:
       }
 
       // Step 3: Intersect base classes of both sides
-      val commonBaseClasses = tp.mapReduceOr(_.baseClasses)(intersect)
+      val commonBaseClasses = tp.mapReduceOr(_.dealias.baseClasses)(intersect)
       val doms = dominators(commonBaseClasses, Nil)
       def baseTp(cls: ClassSymbol): Type =
         tp.baseType(cls).mapReduceOr(identity)(mergeRefinedOrApplied)

Original file line number	Diff line number	Diff line change
`@@ -345,7 +345,7 @@ object TypeOps:`
`345`	`345`	`}`
`346`	`346`
`347`	`347`	`// Step 3: Intersect base classes of both sides`
`348`		`- val commonBaseClasses = tp.mapReduceOr(_.baseClasses)(intersect)`
	`348`	`+ val commonBaseClasses = tp.mapReduceOr(_.dealias.baseClasses)(intersect)`
`349`	`349`	`val doms = dominators(commonBaseClasses, Nil)`
`350`	`350`	`def baseTp(cls: ClassSymbol): Type =`
`351`	`351`	`tp.baseType(cls).mapReduceOr(identity)(mergeRefinedOrApplied)`