#2687 Typing and crash with CH input

[john]

The crash is very repeatable.
1. You create a new map. Press enter to create a node.
2. In usual EN typing, you can instantly type once you hover your cursor to the node. If your input method is CN Cangjie 倉頡, if you hover to the node and type CN character, in most of the case once you finish typing the code, and try to select a character using spacebar, the Freeplane will crash, about 60-90%-ish of the time.
3. If you avoid the hover-then-type sequence, and explicitly double click the node until the typing flashing cursor appears, then any typing would be safe and crash nothing.
4. This only happens in CN Cangjie. CN Pinyin crashes nothing. There may be some other input method that would crash the program too.