Fixes crash in history view. The crash occurs with the following

sequence:

1. Delete a day of history.
2. Before the delete finishes, click to delete another day.
3. While the modal dialog is up wait for the delete/reload to
   complete.
4. Click ok.

This crashes because the index supplied to delete in step 2 is bogus
after step 3 completes.

I suspect we could make this a bit more elegant, but I'm holding off
until we figure out the HTML versions of these.

BUG=1358107
TEST=Make sure history deletion still works.

Review URL: http://codereview.chromium.org/602

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@1708 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 20 insertions, 0 deletions

diff --git a/chrome/browser/history_model.cc b/chrome/browser/history_model.cc
index 36317c2..23d3456 100644
--- a/chrome/browser/history_model.cc
+++ b/chrome/browser/history_model.cc
@@ -182,6 +182,20 @@ void HistoryModel::Refresh() {
     observer_->ModelEndWork();
   search_depth_ = 0;
   InitVisitRequest(search_depth_);
+
+  if (results_.size() > 0) {
+    // There are results and we've been asked to reload. If we don't swap out
+    // the results now, the view is left holding indices that are going to
+    // change as soon as the load completes, which poses problems for deletion.
+    // In particular, if the user deletes a range, then clicks on delete again
+    // a modal dialog is shown. If during the time the modal dialog is shown
+    // and the user clicks ok the load completes, the index passed to delete is
+    // no longer valid. To avoid this we empty out the results immediately.
+    history::QueryResults empty_results;
+    results_.Swap(&empty_results);
+    if (observer_)
+      observer_->ModelChanged(true);
+  }
 }
 
 void HistoryModel::Observe(NotificationType type,
diff --git a/chrome/browser/history_view.cc b/chrome/browser/history_view.cc
index 0c8043b..5add4fc 100644
--- a/chrome/browser/history_view.cc
+++ b/chrome/browser/history_view.cc
@@ -1256,6 +1256,12 @@ void HistoryView::DeleteDayAtModelIndex(int index) {
     return;
   }
 
+  if (index < 0 || index >= model_->GetItemCount()) {
+    // Bogus index.
+    NOTREACHED();
+    return;
+  }
+
   UserMetrics::RecordAction(L"History_DeleteHistory", model_->profile());
 
   // BrowsingDataRemover deletes itself when done.