Fix linker's handling of malformed function references.

pkg/analyzer/test/src/summary/linker_test.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/summary/format.dart';
+import 'package:analyzer/src/summary/idl.dart';
 import 'package:analyzer/src/summary/link.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
 import 'summarize_ast_test.dart';
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(LinkerUnitTest);
 }
@@ skipping 580 matching lines @@
     addNamedSource('/b.dart', '');
     createLinker('import "a.dart"; import "b.dart";');
     LibraryElementForLink libA = getLibrary('file:///a.dart');
     LibraryElementForLink libB = getLibrary('file:///b.dart');
     LibraryCycleForLink libraryCycle = testLibrary.libraryCycleForLink;
     expect(libraryCycle.dependencies,
         unorderedEquals([libA.libraryCycleForLink, libB.libraryCycleForLink]));
     expect(libraryCycle.libraries, [testLibrary]);
   }
 
+  void test_malformed_function_reference() {
+    // Create a corrupted package bundle in which the inferred type of `x`
+    // refers to a non-existent local function.
+    var bundle = createPackageBundle('var x = () {}', path: '/a.dart');
+    expect(bundle.linkedLibraries, hasLength(1));
+    expect(bundle.linkedLibraries[0].units, hasLength(1));
+    for (LinkedReferenceBuilder ref
+        in bundle.linkedLibraries[0].units[0].references) {
+      if (ref.kind == ReferenceKind.function) {
+        ref.localIndex = 1234;
+      }
+    }
+    addBundle(bundle);
+    createLinker('''
+import 'a.dart';
+var y = x;
+''');
+    LibraryElementForLink library = linker.getLibrary(linkerInputs.testDartUri);
+    expect(
+        library
+            .getContainedName('y')
+            .asTypeInferenceNode
+            .variableElement
+            .inferredType
+            .toString(),
+        'dynamic');
+  }
+
   void test_multiplyInheritedExecutable_differentSignatures() {
     createLinker('''
 class B {
   void f() {}
 }
 abstract class I {
    f();
 }
 class C extends B with I {}
 class D extends C {
@@ skipping 99 matching lines @@
     TypeParameterElementImpl t = c.typeParameters[0];
     TypeParameterElementImpl u = c.typeParameters[1];
     TypeParameterElementImpl v = d.typeParameters[0];
     TypeParameterElementImpl w = d.typeParameters[1];
     expect(c.isTypeParameterInScope(v), false);
     expect(c.isTypeParameterInScope(w), false);
     expect(d.isTypeParameterInScope(t), false);
     expect(d.isTypeParameterInScope(u), false);
   }
 }