More closely match previous behavior

ahejlsberg · ahejlsberg · commit d45806a9844d · 2021-05-23T17:03:11.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -24122,7 +24122,7 @@ namespace ts {
         }
 
         function isGenericTypeWithUnionConstraint(type: Type) {
-            return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & TypeFlags.Union);
+            return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & (TypeFlags.Nullable | TypeFlags.Union));
         }
 
         function containsGenericType(type: Type): boolean {

Original file line number	Diff line number	Diff line change
`@@ -24122,7 +24122,7 @@ namespace ts {`
`24122`	`24122`	`}`
`24123`	`24123`
`24124`	`24124`	`function isGenericTypeWithUnionConstraint(type: Type) {`
`24125`		`- return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & TypeFlags.Union);`
	`24125`	`+ return !!(type.flags & TypeFlags.Instantiable && getBaseConstraintOrType(type).flags & (TypeFlags.Nullable \| TypeFlags.Union));`
`24126`	`24126`	`}`
`24127`	`24127`
`24128`	`24128`	`function containsGenericType(type: Type): boolean {`