Properly check T[K] constraints in type relationships

ahejlsberg · ahejlsberg · commit fc641fa2752d · 2017-01-09T16:51:30.000-08:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -7206,7 +7206,7 @@ namespace ts {
                     return related === RelationComparisonResult.Succeeded;
                 }
             }
-            if (source.flags & TypeFlags.StructuredOrTypeParameter || target.flags & TypeFlags.StructuredOrTypeParameter) {
+            if (source.flags & TypeFlags.StructuredOrTypeVariable || target.flags & TypeFlags.StructuredOrTypeVariable) {
                 return checkTypeRelatedTo(source, target, relation, undefined, undefined, undefined);
             }
             return false;
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
@@ -2803,7 +2803,7 @@ namespace ts {
         EnumLike = Enum | EnumLiteral,
         UnionOrIntersection = Union | Intersection,
         StructuredType = Object | Union | Intersection,
-        StructuredOrTypeParameter = StructuredType | TypeParameter | Index,
+        StructuredOrTypeVariable = StructuredType | TypeParameter | Index | IndexedAccess,
         TypeVariable = TypeParameter | IndexedAccess,
 
         // 'Narrowable' types are types where narrowing actually narrows.

Original file line number	Diff line number	Diff line change
`@@ -7206,7 +7206,7 @@ namespace ts {`
`7206`	`7206`	`return related === RelationComparisonResult.Succeeded;`
`7207`	`7207`	`}`
`7208`	`7208`	`}`
`7209`		`- if (source.flags & TypeFlags.StructuredOrTypeParameter \|\| target.flags & TypeFlags.StructuredOrTypeParameter) {`
	`7209`	`+ if (source.flags & TypeFlags.StructuredOrTypeVariable \|\| target.flags & TypeFlags.StructuredOrTypeVariable) {`
`7210`	`7210`	`return checkTypeRelatedTo(source, target, relation, undefined, undefined, undefined);`
`7211`	`7211`	`}`
`7212`	`7212`	`return false;`