Multi-tab: Fixing TabStripSelectionModel::SetSelectedIndex corner case.

BUG=Invoking SetSelectedIndex(-1) results in stack overflow.
TEST=NONE


Review URL: http://codereview.chromium.org/7140001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@88433 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/tabs/tab_strip_selection_model.cc

@@ -59,7 +59,9 @@ void TabStripSelectionModel::DecrementFrom(int index) {
 
 void TabStripSelectionModel::SetSelectedIndex(int index) {
   anchor_ = active_ = index;
-  SetSelectionFromAnchorTo(index);
+  selected_indices_.clear();
+  if (index != kUnselectedIndex)
+    selected_indices_.push_back(index);
 }
 
 bool TabStripSelectionModel::IsSelected(int index) const {

chrome/browser/tabs/tab_strip_selection_model_unittest.cc

@@ -40,6 +40,13 @@ TEST_F(TabStripSelectionModelTest, SetSelectedIndex) {
   EXPECT_FALSE(model.empty());
 }
 
+TEST_F(TabStripSelectionModelTest, SetSelectedIndexToEmpty) {
+  TabStripSelectionModel model;
+  model.SetSelectedIndex(-1);
+  EXPECT_EQ("active=-1 anchor=-1 selection=", StateAsString(model));
+  EXPECT_TRUE(model.empty());
+}
+
 TEST_F(TabStripSelectionModelTest, IncrementFrom) {
   TabStripSelectionModel model;
   model.SetSelectedIndex(1);
@@ -99,6 +106,22 @@ TEST_F(TabStripSelectionModelTest, RemoveIndexFromSelection) {
   EXPECT_EQ("active=2 anchor=2 selection=", StateAsString(model));
 }
 
+TEST_F(TabStripSelectionModelTest, SetSelectionFromAnchorTo) {
+  TabStripSelectionModel model;
+  model.SetSelectedIndex(2);
+  model.SetSelectionFromAnchorTo(7);
+  EXPECT_EQ("active=7 anchor=2 selection=2 3 4 5 6 7", StateAsString(model));
+
+  model.Clear();
+  model.SetSelectedIndex(7);
+  model.SetSelectionFromAnchorTo(2);
+  EXPECT_EQ("active=2 anchor=7 selection=2 3 4 5 6 7", StateAsString(model));
+
+  model.Clear();
+  model.SetSelectionFromAnchorTo(7);
+  EXPECT_EQ("active=7 anchor=7 selection=7", StateAsString(model));
+}
+
 TEST_F(TabStripSelectionModelTest, Clear) {
   TabStripSelectionModel model;
   model.SetSelectedIndex(2);