Merge pull request #15442 from dotty-staging/fix-15293

odersky · web-flow · commit bf026ad4f134 · 2022-06-15T19:39:52.000+02:00
Recover from TypeErrors in isErroneous
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -354,7 +354,8 @@ object Types {
      *
      */
     def isErroneous(using Context): Boolean =
-      widen.existsPart(_.isError, forceLazy = false)
+      try widen.existsPart(_.isError, forceLazy = false)
+      catch case ex: TypeError => true
 
     /** Is this type unusable for implicit search or overloading resolution
      *  since it has embedded errors that can match anything? This is weaker and more

Original file line number	Diff line number	Diff line change
`@@ -354,7 +354,8 @@ object Types {`
`354`	`354`	`*`
`355`	`355`	`*/`
`356`	`356`	`def isErroneous(using Context): Boolean =`
`357`		`- widen.existsPart(_.isError, forceLazy = false)`
	`357`	`+ try widen.existsPart(_.isError, forceLazy = false)`
	`358`	`+ catch case ex: TypeError => true`
`358`	`359`
`359`	`360`	`/** Is this type unusable for implicit search or overloading resolution`
`360`	`361`	`* since it has embedded errors that can match anything? This is weaker and more`