Don't log stack trace for a bad package URL in a source file.

pkg/analyzer/lib/src/generated/source.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.source;
 
 import 'dart:collection';
 import "dart:math" as math;
 
 import 'package:analyzer/file_system/file_system.dart';
@@ skipping 816 matching lines @@
         throw new AnalysisException(
             "Cannot resolve a relative URI without a containing source: $containedUri");
       }
       containedUri = containingSource.resolveRelativeUri(containedUri);
     }
 
     Uri actualUri = containedUri;
 
     // Check .packages and update target and actual URIs as appropriate.
     if (_packages != null && containedUri.scheme == 'package') {
-      Uri packageUri =
-          _packages.resolve(containedUri, notFound: (Uri packageUri) => null);
+      Uri packageUri = null;
+      try {
+        packageUri =
+            _packages.resolve(containedUri, notFound: (Uri packageUri) => null);
+      } on ArgumentError {
+        // Fall through to try resolvers.
+      }
 
       if (packageUri != null) {

[Brian Wilkerson, 2016/01/09 16:02:39]

This 'if' ought to be inside the 'try' because packageUri will only be non-null
if an exception is not thrown.

[skybrian, 2016/01/09 19:26:45]

That's true but it seems like it would be less clear because my intention is to
only ignore exceptions thrown by _packages.resolve, not within .replace (for
example).

[Brian Wilkerson, 2016/01/10 16:55:25]

I disagree (hence the comment), but it's your call (I already gave an
unqualified LGTM because I agree that it's semantically valid).

         // Ensure scheme is set.
         if (packageUri.scheme == '') {
           packageUri = packageUri.replace(scheme: 'file');
         }
         containedUri = packageUri;
       }
     }
 
     for (UriResolver resolver in _resolvers) {
       Source result = resolver.resolveAbsolute(containedUri, actualUri);
@@ skipping 240 matching lines @@
   Source resolveAbsolute(Uri uri, [Uri actualUri]);
 
   /**
    * Return an absolute URI that represents the given [source], or `null` if a
    * valid URI cannot be computed.
    *
    * The computation should be based solely on [source.fullName].
    */
   Uri restoreAbsolute(Source source) => null;
 }