fixes #200, library prefixes for unknown imports

lib/src/utils.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.
 
 /// Holds a couple utility functions used at various places in the system.
 library dev_compiler.src.utils;
 
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
@@ skipping 189 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;
 }
 
-bool isDynamicTarget(Expression node) =>
-    node != null && !isLibraryPrefix(node) && node.staticType.isDynamic;
+bool isDynamicTarget(Expression node) {
+  if (node == null) return false;
+
+  if (isLibraryPrefix(node)) return false;
+
+  // Null type happens when we have unknown identifiers, like a dart: import
+  // that doesn't resolve.
+  var type = node.staticType;
+  return type == null || type.isDynamic;
+}
 
 bool isLibraryPrefix(Expression node) =>
     node is SimpleIdentifier && node.staticElement is PrefixElement;
 
 /// Returns an ANSII color escape sequence corresponding to [levelName]. Colors
 /// are defined for: severe, error, warning, or info. Returns null if the level
 /// name is not recognized.
 String colorOf(String levelName) {
   levelName = levelName.toLowerCase();
   if (levelName == 'shout' || levelName == 'severe' || levelName == 'error') {
@@ skipping 231 matching lines @@
   int lineEnd = endLoc.offset;
   int unitEnd = unit.endToken.end;
   int lineNum = lineInfo.getLocation(lineEnd).lineNumber;
   while (lineEnd < unitEnd &&
       lineInfo.getLocation(++lineEnd).lineNumber == lineNum);
 
   var text = content.substring(start, end);
   var lineText = content.substring(lineStart, lineEnd);
   return new SourceSpanWithContext(startLoc, endLoc, text, lineText);
 }