Fix stacktrace crasher bug in the VM and duplicate breakpoint crasher bug.

runtime/vm/debugger.cc

 // 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.
 
 #include "vm/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 1714 matching lines @@
     intptr_t line_number;
     script.GetTokenLocation(token_pos, &line_number, NULL);
     OS::Print("Registering pending breakpoint for "
               "uncompiled function '%s' at line %" Pd "\n",
               func.ToFullyQualifiedCString(),
               line_number);
   }
   SourceBreakpoint* bpt = GetSourceBreakpoint(script, token_pos);
   if (bpt == NULL) {
     bpt = new SourceBreakpoint(nextId(), script, token_pos, last_token_pos);
+    RegisterSourceBreakpoint(bpt);
   }
-  RegisterSourceBreakpoint(bpt);
   bpt->Enable();
   return bpt;
 }
 
 
 // Synchronize the enabled/disabled state of all code breakpoints
 // associated with the source breakpoint bpt.
 void Debugger::SyncBreakpoint(SourceBreakpoint* bpt) {
   CodeBreakpoint* cbpt = code_breakpoints_;
   while (cbpt != NULL) {
@@ skipping 701 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart