Report malformed URIs in library dependencies

pkg/compiler/lib/src/library_loader.dart

 // Copyright (c) 2012, 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 dart2js.library_loader;
 
 import 'dart:async';
 
 import 'dart2jslib.dart' show
     Compiler,
@@ skipping 481 matching lines @@
                 compiler.reportError(unit, MessageKind.MISSING_PART_OF_TAG);
               }
             });
           });
     });
   }
 
   /**
    * Handle an import/export tag by loading the referenced library and
    * registering its dependency in [handler] for the computation of the import/
-   * export scope.
+   * export scope. If the tag does not contain a valid URI, then its dependency
+   * is not registered in [handler].
    */
-  Future registerLibraryFromTag(LibraryDependencyHandler handler,
-                                LibraryElement library,
-                                LibraryDependency tag) {
+  Future<Null> registerLibraryFromTag(LibraryDependencyHandler handler,
+                                      LibraryElement library,
+                                      LibraryDependency tag) {
     Uri base = library.canonicalUri;
-    Uri resolvedUri = base.resolve(tag.uri.dartString.slowToString());
+    String tagUriString = tag.uri.dartString.slowToString();
+    Uri resolvedUri;
+    try {
+      resolvedUri = base.resolve(tagUriString);
+    } on FormatException {
+      compiler.reportError(
+          tag.uri, MessageKind.INVALID_URI, {'uri': tagUriString});
+      // 'reportError' does not stop necessarily stop compilation
+      return new Future.value();
+    }
     return createLibrary(handler, library, resolvedUri, tag.uri)
         .then((LibraryElement loadedLibrary) {
           if (loadedLibrary == null) return;
           compiler.withCurrentElement(library, () {
             handler.registerDependency(library, tag, loadedLibrary);
           });
         });
   }
 
   /**
@@ skipping 667 matching lines @@
         }
         suffixes.add(const Link<Uri>().prepend(canonicalUri));
       }
       suffixChainMap[library] = suffixes;
       return;
     }
 
     computeSuffixes(rootLibrary, const Link<Uri>());
   }
 }