Bug 330224

Description Bilal Alsallakh 2010-11-15 06:26:53 EST

Build Identifier: M20090917-0800

The fix introduced in Bug# 290547 solves half of the problem, here i will explain the remaining half:

A grid has five colulmns and three column groups.
The first ColumnGroup contains the first column only. The second group contains the next 3 columns, and the 3rd group contains the last column.

The current code causes an SWT error:

            for (int i = 0; i < order.length; i++)
            {
                GridColumn col = getColumn(order[i]);

                if (currentGroup != null)
                {

                    if (col.getColumnGroup() != currentGroup && colsInGroup > 0 )
                    {
                        SWT.error(SWT.ERROR_INVALID_ARGUMENT);
                    }
                    else
                    {
                        colsInGroup--;
                        if (colsInGroup <= 0)
                        {
                            currentGroup = null;
                        }
                    }
                }
                else if (col.getColumnGroup() != null)
                {
                    currentGroup = col.getColumnGroup();
                    colsInGroup = currentGroup.getColumns().length - 1;
                }
            }
        }

Analysis:

After the first iteration, currentGroup is set to the 1st group, colsInGroup is set to 0.
After the 2nd iteration, currentGroup is set to null, colsInGroup is set to -1.
After the 3rd iteration, currentGroup is set to 2ndGroup. colsInGroup is set to 2 (which is wrong since we are already in the 2nd column in the current group..).
After the 4rd iteration, currentGroup is set to 2ndGroup. colsInGroup is set to 1
In the fifth iteration -> crash (since we have a new group but colsInGroup is still > 0).


patch:

            for (int i = 0; i < order.length; i++)
            {
                GridColumn col = getColumn(order[i]);

                if (currentGroup != null)
                {
                    if (col.getColumnGroup() != currentGroup)
                    {
                        if (colsInGroup > 0 )
                        {
                            SWT.error(SWT.ERROR_INVALID_ARGUMENT);
                        }
                        else
                        {
                            currentGroup = col.getColumnGroup();
                            if (currentGroup != null) {
                                colsInGroup = currentGroup.getColumns().length - 1;
                            }
                        }
                    }
                    else
                    {
                        colsInGroup--;
                        if (colsInGroup <= 0)
                        {
                            currentGroup = null;
                        }
                    }
                }
                else if (col.getColumnGroup() != null)
                {
                    currentGroup = col.getColumnGroup();
                    colsInGroup = currentGroup.getColumns().length - 1;
                }
            }
        }


Reproducible: Always

Steps to Reproduce:
create a group with five colulmns and three column groups.
The first ColumnGroup contains the first column only. The second group contains the next 3 columns, and the 3rd group contains the last column.