Fixed: issue when opening a popUpList of a CPComboBox. We now firstly open the panel and then we modify the content of the panel, this occured an issue with the rendering of the view

AppKit/CPComboBox.j

@@ -518,8 +518,6 @@ var CPComboBoxTextSubview = @"text",
     if (!_listDelegate)
         [self setListDelegate:[[_CPPopUpList alloc] initWithDataSource:self]];
 
-    [self _selectMatchingItem];
-
     // Note the offset here is 1 less than the focus ring width because the outer edge
     // of the focus ring is very transparent and it looks better if the list is closer.
     if (CPComboBoxFocusRingWidth < 0)
@@ -530,6 +528,7 @@ var CPComboBoxTextSubview = @"text",
     }
 
     [_listDelegate popUpRelativeToRect:[self _borderFrame] view:self offset:CPComboBoxFocusRingWidth - 1];
+    [self _selectMatchingItem];
 }
 
 /*! @ignore */

AppKit/_CPPopUpList.j

@@ -336,6 +336,11 @@ var ListColumnIdentifier = @"1";
     if ([_panel isVisible])
         return;
 
+    [self listWillPopUp];
+
+    [_panel _trapNextMouseDown];
+    [[aView window] addChildWindow:_panel ordered:CPWindowAbove];
+
     var rowRect = [_tableView rectOfRow:[self numberOfRowsInTableView:_tableView] - 1],
         frame = CGRectMake(0, 0, MAX(_listWidth, CGRectGetWidth(aRect)), CGRectGetMaxY(rowRect));
 
@@ -346,11 +351,6 @@ var ListColumnIdentifier = @"1";
     [_scrollView setFrameSize:CGSizeMakeCopy(frame.size)];
     [_tableView setEnabled:[_dataSource numberOfItemsInList:self] > 0];
     [self scrollItemAtIndexToTop:[_tableView selectedRow]];
-
-    [self listWillPopUp];
-
-    [_panel _trapNextMouseDown];
-    [[aView window] addChildWindow:_panel ordered:CPWindowAbove];
 }
 
 #pragma mark Setting Display Attributes