Fix for resynthesis when a part URI is empty.

pkg/analyzer/lib/src/summary/link.dart

Index: pkg/analyzer/lib/src/summary/link.dart
diff --git a/pkg/analyzer/lib/src/summary/link.dart b/pkg/analyzer/lib/src/summary/link.dart
index 5c70e57bbd0209aa89ff7e4d43078d112ff10684..7d793315ee2f1dfccbbb04d2c5e3347f3ccaf5eb 100644
--- a/pkg/analyzer/lib/src/summary/link.dart
+++ b/pkg/analyzer/lib/src/summary/link.dart
@@ -3520,10 +3520,12 @@ abstract class LibraryElementForLink<
       ];
       int numParts = definingUnit.parts.length;
       for (int i = 0; i < numParts; i++) {
-        // TODO(paulberry): make sure we handle the case where
-        // resolveRelativeUri fails.
         String partRelativeUriStr = definingUnit.publicNamespace.parts[i];
 
+        if (partRelativeUriStr.isEmpty) {
+          continue;
+        }
+
         Uri partRelativeUri;
         try {
           partRelativeUri = Uri.parse(partRelativeUriStr);