Only obtain regular type of fresh object literal type if necessary

ahejlsberg · ahejlsberg · commit 758cdf337872 · 2015-08-30T15:07:04.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -4640,7 +4640,9 @@ namespace ts {
                     // and intersection types are further deconstructed on the target side, we don't want to
                     // make the check again (as it might fail for a partial target type). Therefore we obtain
                     // the regular source type and proceed with that.
-                    source = getRegularTypeOfObjectLiteral(source);
+                    if (target.flags & TypeFlags.UnionOrIntersection) {
+                        source = getRegularTypeOfObjectLiteral(source);
+                    }
                 }
 
                 let saveErrorInfo = errorInfo;
