[debugger] negative conditional break points mute breaks and exceptions.

src/debug/debug-scopes.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/debug/debug-scopes.h"
 
 #include "src/ast/scopes.h"
 #include "src/debug/debug.h"
 #include "src/frames-inl.h"
 #include "src/globals.h"
@@ skipping 40 matching lines @@
   bool collect_non_locals = (option == COLLECT_NON_LOCALS);
   if (!ignore_nested_scopes && shared_info->HasDebugInfo()) {
     // The source position at return is always the end of the function,
     // which is not consistent with the current scope chain. Therefore all
     // nested with, catch and block contexts are skipped, and we can only
     // inspect the function scope.
     // This can only happen if we set a break point inside right before the
     // return, which requires a debug info to be available.
     Handle<DebugInfo> debug_info(shared_info->GetDebugInfo());
 
-    // PC points to the instruction after the current one, possibly a break
-    // location as well. So the "- 1" to exclude it from the search.
-    Address call_pc = GetFrame()->pc() - 1;
-
     // Find the break point where execution has stopped.
-    BreakLocation location = BreakLocation::FromAddress(debug_info, call_pc);
+    BreakLocation location = BreakLocation::FromFrame(debug_info, GetFrame());
 
     ignore_nested_scopes = location.IsReturn();
   }
 
   if (ignore_nested_scopes) {
     if (scope_info->HasContext()) {
       context_ = Handle<Context>(context_->declaration_context(), isolate_);
     } else {
       while (context_->closure() == *function) {
         context_ = Handle<Context>(context_->previous(), isolate_);
@@ skipping 739 matching lines @@
         isolate_, value, Object::GetPropertyOrElement(extension, key), false);
     RETURN_ON_EXCEPTION_VALUE(
         isolate_, JSObject::SetOwnPropertyIgnoreAttributes(
             scope_object, key, value, NONE), false);
   }
   return true;
 }
 
 }  // namespace internal
 }  // namespace v8