Make TypeSystem.resolveToBound() do what it promised in the documentation.

scheglov · commit-bot@chromium.org · commit 4d30d9cffc45 · 2019-08-08T18:32:49.000Z
Initial: https://dart-review.googlesource.com/c/sdk/+/110757 Reverted: https://dart-review.googlesource.com/c/sdk/+/112274 Change-Id: I85fbd7782730b9f44d972a1c807b191e068beff5 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/112303 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/CHANGELOG.md b/pkg/analyzer/CHANGELOG.md
@@ -14,6 +14,8 @@
 * Deprecated InheritanceManager2, and replaced with InheritanceManager3.
   InheritanceManager3 returns ExecutableElements, not FunctionType(s).
 * Added the optional parameter `path` to `parseString`.
+* Changed `TypeSystem.resolveToBound(DartType)` implementation to do
+  what its documentation says.
 
 ## 0.37.0
 * Removed deprecated getter `DartType.isUndefined`.
diff --git a/pkg/analyzer/lib/src/generated/type_system.dart b/pkg/analyzer/lib/src/generated/type_system.dart
@@ -2633,7 +2633,31 @@ abstract class TypeSystem implements public.TypeSystem {
 
   @override
   DartType resolveToBound(DartType type) {
-    return instantiateToBounds(type);
+    if (type is TypeParameterTypeImpl) {
+      var element = type.element;
+
+      var bound = element.bound as TypeImpl;
+      if (bound == null) {
+        return typeProvider.objectType;
+      }
+
+      NullabilitySuffix nullabilitySuffix = type.nullabilitySuffix;
+      NullabilitySuffix newNullabilitySuffix;
+      if (nullabilitySuffix == NullabilitySuffix.question ||
+          bound.nullabilitySuffix == NullabilitySuffix.question) {
+        newNullabilitySuffix = NullabilitySuffix.question;
+      } else if (nullabilitySuffix == NullabilitySuffix.star ||
+          bound.nullabilitySuffix == NullabilitySuffix.star) {
+        newNullabilitySuffix = NullabilitySuffix.star;
+      } else {
+        newNullabilitySuffix = NullabilitySuffix.none;
+      }
+
+      var resolved = resolveToBound(bound) as TypeImpl;
+      return resolved.withNullability(newNullabilitySuffix);
+    }
+
+    return type;
   }
 
   /**
