Recover from TypeErrors in isErroneous

odersky · odersky · commit 5c3ef810d1e8 · 2022-06-14T17:38:39.000+02:00
Fixes #15283 (hopefully)
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -353,7 +353,8 @@ 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
`@@ -353,7 +353,8 @@ object Types {`
`353`	`353`	`*`
`354`	`354`	`*/`
`355`	`355`	`def isErroneous(using Context): Boolean =`
`356`		`- widen.existsPart(_.isError, forceLazy = false)`
	`356`	`+ try widen.existsPart(_.isError, forceLazy = false)`
	`357`	`+ catch case ex: TypeError => true`
`357`	`358`
`358`	`359`	`/** Is this type unusable for implicit search or overloading resolution`
`359`	`360`	`* since it has embedded errors that can match anything? This is weaker and more`