Remove the outermost folded frame for terse stack traces.

lib/src/chain.dart

 // Copyright (c) 2013, 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 stack_trace.chain;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'frame.dart';
@@ skipping 137 matching lines @@
   /// This is useful for limiting the amount of library code that appears in a
   /// stack trace by only showing user code and code that's called by user code.
   ///
   /// If [terse] is true, this will also fold together frames from the core
   /// library or from this package, and simplify core library frames as in
   /// [Trace.terse].
   Chain foldFrames(bool predicate(Frame frame), {bool terse: false}) {
     var foldedTraces = traces.map(
         (trace) => trace.foldFrames(predicate, terse: terse));
     var nonEmptyTraces = foldedTraces.where((trace) {
-      // Ignore traces that contain only folded frames. These traces will be
-      // folded into a single frame each.
-      return trace.frames.length > 1;
+      // Ignore traces that contain only folded frames.
+      if (trace.frames.length > 1) return true;
+
+      // In terse mode, the trace may have removed an outer folded frame,
+      // leaving a single non-folded frame. We can detect a folded frame because
+      // it has no line information.
+      if (!terse) return false;
+      return trace.frames.single.line != null;
     });
 
     // If all the traces contain only internal processing, preserve the last
     // (top-most) one so that the chain isn't empty.
     if (nonEmptyTraces.isEmpty && foldedTraces.isNotEmpty) {
       return new Chain([foldedTraces.last]);
     }
 
     return new Chain(nonEmptyTraces);
   }
 
   /// Converts [this] to a [Trace].
   ///
   /// The trace version of a chain is just the concatenation of all the traces
   /// in the chain.
   Trace toTrace() => new Trace(flatten(traces.map((trace) => trace.frames)));
 
   String toString() => traces.join(_GAP);
 }