Maximum call stack size exceeded on tree selection

[martin-fleck-at]

Bug Description:

For large trees, the depth first iterator causes a Maximum call stack size exceeded during range selection. The main culprit is probably the stack.push(...[]) usage.

Steps to Reproduce:

1. Have any large enough tree in the tree viewer widget. For me, the limit is hit with about 130k nodes.
2. Select a node through mouse click and with Shift select another node to trigger a range selection
3. In the UI nothing visibly happens but in the log you get the following error:

tree-iterator.ts:210 Uncaught RangeError: Maximum call stack size exceeded
    at Object.depthFirst (tree-iterator.ts:210)
    at depthFirst.next (<anonymous>)
    at TreeSelectionState.selectionRange (tree-selection-state.ts:195)
    at TreeSelectionState.selection (tree-selection-state.ts:82)
    at TreeSelectionServiceImpl.transiteTo (tree-selection-impl.ts:86)
    at TreeSelectionServiceImpl.addSelection (tree-selection-impl.ts:77)
    at TreeModelImpl.addSelection (tree-model.ts:436)
    at TreeModelImpl.selectRange (tree-model.ts:452)

Additional Information

• Operating System: Ubuntu
• Theia Version: latest master