[ExtJS 4.2.0.179] 'lastVisibleColumn not defined' when closing tab with grid

[xmoravej]

Hello,
I recently migrated from 4.0.7 to 4.2.0.179 Beta and I started getting occasional ' 'lastVisibleColumn not defined' errors when closing a tab that contains a grid. When the error occurred, the GUI remained messed up - the tab contents disappeared, but the tab header remained visible and did not respond to close attempts.

I implemented a hotfix using the following override that includes a lastColumnVisible null check. It solved my problem.

Ext.override( Ext.grid.header.Container, {
        getGridColumns : function ( refreshCache /* private - used in recursion*/, inResult, hiddenAncestor )
        {
          if ( !refreshCache && this.gridDataColumns )
          {
            return this.gridDataColumns;
          }

          var me = this,
              result = inResult || [],
              items, i, len, item,
              lastVisibleColumn;

          hiddenAncestor = hiddenAncestor || me.hidden;
          if ( me.items )
          {
            items = me.items.items;
            for ( i = 0, len = items.length; i < len; i++ )
            {
              item = items[i];
              if ( item.isGroupHeader )
              {
                item.getGridColumns( true, result, hiddenAncestor );
              }
              else
              {
                item.hiddenAncestor = hiddenAncestor;
                result.push( item );
              }
            }
          }
          me.gridDataColumns = result;

          // If top level, correct first and last visible column flags
          if ( !inResult && len )
          {
            // Set firstVisible and lastVisible flags
            for ( i = 0, len = result.length; i < len; i++ )
            {
              item = result[i];
              item.isFirstVisible = item.isLastVisible = false;
              if ( !item.hidden || item.hiddenAncestor )
              {
                if ( !lastVisibleColumn )
                {
                  item.isFirstVisible = true;
                }
                lastVisibleColumn = item;
              }
            }

            // FIX: added lastVisibleColumn null check
            if ( lastVisibleColumn != null )
            {
              lastVisibleColumn.isLastVisible = true;
            }
          }

          return result;
        }
      } );

[mitchellsimoens]

Can I get a test case to reproduce the error?

[xmoravej]

Hello Mitchell,
I have not put together any simplified test case yet as I seemed to have 'fixed' the problem by adding the null check. Because I have not observed any negative consequences in the app I did not investigate the issue further.

Would a screenshot of the app's layout help?

Cheers,
Jan