Checker is defensive against unresolved redirecting constructor

pkg/analyzer/lib/src/task/strong/checker.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // TODO(jmesserly): this was ported from package:dev_compiler, and needs to be
 // refactored to fit into analyzer.
 library analyzer.src.task.strong.checker;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 565 matching lines @@
 
   @override
   void visitFunctionExpressionInvocation(FunctionExpressionInvocation node) {
     checkFunctionApplication(node, node.function, node.argumentList);
     node.visitChildren(this);
   }
 
   @override
   void visitRedirectingConstructorInvocation(
       RedirectingConstructorInvocation node) {
-    var type = node.staticElement.type;
-    checkArgumentList(node.argumentList, type);
+    var type = node.staticElement?.type;
+    // TODO(leafp): There's a TODO in visitRedirectingConstructorInvocation
+    // in the element_resolver to handle the case that the element is null
+    // and emit an error.  In the meantime, just be defensive here.
+    if (type != null) {
+      checkArgumentList(node.argumentList, type);
+    }
     node.visitChildren(this);
   }
 
   @override
   void visitSuperConstructorInvocation(SuperConstructorInvocation node) {
     var element = node.staticElement;
     if (element != null) {
       var type = node.staticElement.type;
       checkArgumentList(node.argumentList, type);
     }
@@ skipping 439 matching lines @@
       }
     } catch (e) {
       // TODO(sigmund): remove this try-catch block (see issue #48).
     }
     if (baseMethod == null || baseMethod.isStatic) return null;
     return baseMethod.type;
   }
   ;
   return f;
 }